Business Statistics The Where Why and How of Data Collection.docx

Business Statistics The Where, Why, and How of Data Collection 1) Statistics is a discipline that involves tools and techniques used to describe data and draw conclusions. Answer: TRUE 2) In this course, the term business statistics refers to the set of tools and techniques that are used to convert information into meaningful data. Answer: FALSE 3) Descriptive statistics allow a decision maker to reach a conclusion about a population based on a subset from the population. Answer: FALSE 4) An accountant has recently prepared a report for a client that contains a variety of graphs and charts. In doing so, she has used descriptive statistical methods. Answer: TRUE 5) Descriptive statistical tools include graphs, charts, and numerical measures. Answer: TRUE 6) A histogram is an example of a numerical measure. Answer: FALSE 7) Companies frequently use charts and graphs in their regular communications with stockholders and investors; this shows the use of descriptive statistics. Answer: TRUE 8) A manufacturing manager has developed a table that shows the average production volume each day for the past three weeks. The average production level is an example of a numerical measure. Answer: TRUE 9) An accountant who recently examined 200 accounts from a company's total of 4,000 accounts in an effort to estimate the percentage of all accounts that have incorrect journal entries is using descriptive statistical analysis to reach the conclusion. Answer: FALSE 10) The editor of a local newspaper is interested in determining the percentage of subscribers who read the paper's editorials. The statistical technique that he would use is called estimation. Answer: TRUE 11) Hypothesis testing and estimation are two statistical tools that are used to draw inferences about a large data set based on a subset of the data. Answer: TRUE Keywords: inferential statistics 12) Another term for the arithmetic average is the mean. Answer: TRUE , mean 13) Statistical inference would be used as the primary statistical tool by a quality control manager who wishes to estimate the average weight of her company's products. Answer: TRUE Keywords: inferential statistics 14) A light bulb manufacturer wants to advertise the average life of its light bulbs so it tests a subset of light bulbs. This is an example of inferential statistics. Answer: TRUE Keywords: inferential statistics 15) A sales manager has five salespeople. The following are the number of units sold by the five salespeople during the past week: {5, 13, 6, 2, 4}. Based on the data, the mean number of units sold was 6 units. Answer: TRUE , mean 16) Some of the most common methods of collecting data include experiments, telephone surveys, mail questionnaires, direct observations, and personal interviews. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 17) An experiment is a process that generates data as its outcome. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 18) Experimental design is a plan for performing an experiment where the effects of one or more factors on the variable of interest are measured. Answer: TRUE Keywords: data collection, experiments Section: 1-2 Procedures for Collecting Data 19) Typically, it is possible to include a larger number of questions in a phone survey than in a mail survey since it takes less time to complete the survey over the phone. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 20) An Internet-based or emailed survey is not an alternative method of data collection. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 21) An open-end question requires respondents to choose from a short list of choices Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 22) A short survey with closed-end questions is likely to have a better response rate than a long survey with open-ended questions. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 23) The Cranston Company recently met with a group of its customers to ask questions about the service and products provided by the company. The data collected in this process would be an example of data collected through direct observation. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 24) The Georgia Company, a pharmaceutical company, recently conducted a study in which 20 people were given a new drug and 20 other people were given a placebo. The objective was to determine whether there was a difference in pain relief between those using the new drug versus those using the placebo. The data collection used here is an example of an experiment. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 25) When comparing experiments, surveys, and direct observation as methods of data collection, the method that would typically be the least expensive is surveys. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 26) Assuming that you are planning to collect data using an experiment, it will be very important to establish an appropriate survey design. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 27) Mail questionnaires typically generate poor response rates. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 28) In an unstructured interview the questions are scripted. Answer: FALSE Keywords: data collection, interviews Section: 1-2 Procedures for Collecting Data 29) One way to improve the response rate for a survey is to administer the surveys directly to the respondents. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 30) On a survey, the questions pertaining to the background of the respondent (age, gender, etc.) are referred to as demographic questions. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 31) When an interviewer asks a specified series of questions in the course of a personal interview, he/she is conducting an unstructured interview. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 32) A company that is interested in determining which of three prices to charge for its products has test marketed the product in three cities, each time using a different price for the product. The number of products sold in the first week is recorded. In this case, the data are considered to have been collected using an experiment. Answer: TRUE Keywords: data collection, survey Section: 1-2 Procedures for Collecting Data 33) Data collected using open-end questions is generally easier to analyze than data collected from closed-end questions. Answer: FALSE Keywords: data collection, survey Section: 1-2 Procedures for Collecting Data 34) One of the advantages of data check sheets is that as the data are being recorded, they are also being displayed in a useful format. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 35) The primary purpose of performing a pre-test when developing a telephone or mail survey is to make sure that the respondents can understand the questions and are able to provide meaningful responses. Answer: TRUE Keywords: data collection, protest Section: 1-2 Procedures for Collecting Data 36) Close-end questions provide the greatest opportunity to obtain ideas and thoughts on the part of those surveyed but the resulting data are more difficult to analyze. Answer: FALSE Keywords: data collection, survey Section: 1-2 Procedures for Collecting Data 37) Questions on a written survey dealing with the characteristics of the respondent (age, income, etc.) are referred to as categorical questions. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 38) Open-end questions are typically included in a survey when the objective is to provide the maximum opportunity for the respondent to express his or her opinion. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 39) The method of data collection called direct observation is always associated with gathering data from people. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 40) Data gathered from a structured interview is generally easier to analyze than data collected from an unstructured interview. Answer: TRUE Keywords: data collection, structured interview Section: 1-2 Procedures for Collecting Data 41) When a survey is done you can always assume that non-respondents would have answered the same way as those who did respond. Answer: FALSE Keywords: data collection, nonresponse bias Section: 1-2 Procedures for Collecting Data 42) When a company scans the bar codes on its products in an effort to count the number of products that remain in inventory, the company is collecting data through experimentation. Answer: FALSE Keywords: data collection, UPC Section: 1-2 Procedures for Collecting Data 43) Data collected on the Internet can generally be considered accurate since the data must go through a screening process before they can be placed on the Internet. Answer: FALSE Keywords: data collection Section: 1-2 Procedures for Collecting Data 44) It is possible for an interviewer to interject bias into the data collection project by the way he or she asks the questions. Answer: TRUE Keywords: data collection, bias Section: 1-2 Procedures for Collecting Data 45) When people fail to respond to a survey, the data collection process may suffer from nonresponse bias. Answer: TRUE Keywords: data collection Section: 1-2 Procedures for Collecting Data 46) Selection bias occurs when the respondent decides which of the questions on the survey to answer. Answer: FALSE Keywords: data collection, bias Section: 1-2 Procedures for Collecting Data 47) Recently, an analyst in a company's marketing department surveyed customers regarding how often they buy a particular product. One customer indicated that she purchased the product 17 times in the last six months, but the analyst recorded the response as 71 times. This is an example of observer bias. Answer: FALSE Keywords: data collection, bias Section: 1-2 Procedures for Collecting Data 48) When the United States conducts a census that counts all people in the country, this is an example of using a sample. Answer: FALSE Keywords: population, sample Section: 1-3 Populations, Samples and Sampling Techniques 49) When the marketing manager for a large company surveys a portion of the total customers of his company, he is using a sample from the population. Answer: TRUE Keywords: sample, population Section: 1-3 Populations, Samples and Sampling Techniques 50) A census is an enumeration of the entire sample of items selected from the population of interest. Answer: FALSE Keywords: sample Section: 1-3 Populations, Samples and Sampling Techniques 51) A sample is selected from a population in cases where selecting data from the entire population is either very difficult or very expensive. Answer: TRUE Keywords: sample Section: 1-3 Populations, Samples and Sampling Techniques 52) A parameter is the boundary on the population of interest. Answer: FALSE Keywords: parameter, population Section: 1-3 Populations, Samples and Sampling Techniques 53) Population parameters are descriptive numerical measures, such as an average, that describe the entire population. Answer: TRUE Keywords: parameter Section: 1-3 Populations, Samples and Sampling Techniques 54) Statistics are measures computed from the entire population of data. Answer: FALSE Keywords: statistics Section: 1-3 Populations, Samples and Sampling Techniques 55) When the production manager selects a sample of items that have been produced on her production line and computes the proportion of those items that are defective, the proportion is referred to as a statistic. Answer: TRUE Keywords: statistics, proportion Section: 1-3 Populations, Samples and Sampling Techniques 56) The First National Bank mailed out a survey to all 3,456 savings account customers. A total of 568 surveys were returned. Values computed from the returned surveys would constitute parameters since all 568 customers were surveyed. Answer: FALSE Keywords: parameter, statistic Section: 1-3 Populations, Samples and Sampling Techniques 57) If an analyst computes statistics from a sample, the sample is by definition a statistical sample. Answer: FALSE Keywords: sample, statistic Section: 1-3 Populations, Samples and Sampling Techniques 58) When a group of university students takes a poll of their fellow students on whether they support a proposed fee increase, the sampling method they would use when students walking near the library are surveyed would be called a random sample. Answer: FALSE Keywords: random sample Section: 1-3 Populations, Samples and Sampling Techniques 59) A pharmaceutical company conducts a study where 50 patients are given a drug. They find that 10 percent of patients experience nausea as a side effect. This 10 percent is an example of a parameter. Answer: FALSE Keywords: parameter, statistic Section: 1-3 Populations, Samples and Sampling Techniques 60) It is possible for a nonstatistical sample to yield statistics that have values closer to the corresponding parameter than will a statistical sample. Answer: TRUE Keywords: nonstatistical sample Section: 1-3 Populations, Samples and Sampling Techniques 61) One of the most common statistical sampling techniques is convenience sampling. Answer: FALSE Keywords: convenience sample Section: 1-3 Populations, Samples and Sampling Techniques 62) Possibly the most frequently used nonstatistical sampling procedure is the simple random sample. Answer: FALSE Keywords: simple random sample Section: 1-3 Populations, Samples and Sampling Techniques 63) A common underpinning of all statistical sampling techniques is the concept of random selection. Answer: TRUE Keywords: random sample Section: 1-3 Populations, Samples and Sampling Techniques 64) Simple random sampling involves selecting members of the population in such as way that all members are equally likely to be chosen. Answer: TRUE Keywords: sampling techniques Section: 1-3 Populations, Samples and Sampling Techniques 65) When stratified random sampling is employed, the population is divided into homogeneous subgroups called strata. Answer: TRUE Keywords: stratified random sample Section: 1-3 Populations, Samples and Sampling Techniques 66) In election years, the polls that are conducted by such companies as Gallup and Harris typically employ stratified random sampling to reduce the number of people that will need to be surveyed. Answer: TRUE Keywords: stratified random sample Section: 1-3 Populations, Samples and Sampling Techniques 67) If a state agency wishes to conduct on-site surveys of small businesses throughout the state, cluster sampling could potentially be used to reduce the geographical area over which the surveys would need to be conducted. Answer: TRUE Keywords: cluster sample Section: 1-3 Populations, Samples and Sampling Techniques 68) Stratified random sampling is the same thing as simple random sampling. Answer: FALSE Keywords: sampling techniques Section: 1-3 Populations, Samples and Sampling Techniques 69) When a small sample is used, a stratified random sample is more likely to provide the desired information than a simple random sample. Answer: TRUE Keywords: sampling techniques Section: 1-3 Populations, Samples and Sampling Techniques 70) Suppose a professor collects survey data by passing out surveys in his/her classes, where the population of interest is defined as all students enrolled at that university. This is an example of nonstatistical sampling technique. Answer: TRUE Keywords: sampling techniques Section: 1-3 Populations, Samples and Sampling Techniques 71) One of the reasons that managers prefer statistical sampling to nonstatistical sampling is that statistical sampling is generally easier to perform and less expensive. Answer: FALSE Keywords: statistical sample Section: 1-3 Populations, Samples and Sampling Techniques 72) A market research firm that surveys customers in a shopping mall by asking various people to respond to a short survey about a new product is performing convenience sampling. Answer: TRUE Keywords: convenience sample Section: 1-3 Populations, Samples and Sampling Techniques 73) If a population is very large, it may be better to select a sample from the population than to try to obtain a census in an effort to reduce measurement error. Answer: TRUE Keywords: measurement error, data collection Section: 1-3 Populations, Samples and Sampling Techniques 74) The sales data for a company measured weekly for the past year would be considered cross-sectional data since the sales values are computed from the entire company. Answer: FALSE Keywords: data type, cross-sectional Section: 1-4 Data Types and Data Measurement Levels 75) When students are asked to list their age and the percentage of their college expenses that they pay for themselves, the type of data being collected is quantitative. Answer: TRUE Keywords: data type, quantitative Section: 1-4 Data Types and Data Measurement Levels 76) It is possible for the same survey questionnaire to yield both quantitative and qualitative data. Answer: TRUE Keywords: data type, quantitative, qualitative Section: 1-4 Data Types and Data Measurement Levels 77) Sales data measured each week for the past twenty weeks are examples of time-series data. Answer: TRUE Keywords: data type, time series Section: 1-4 Data Types and Data Measurement Levels 78) Recording vehicle type as sedan, minivan, pick-up truck, etc. is an example of qualitative data. Answer: TRUE Keywords: data type Section: 1-4 Data Types and Data Measurement Levels 79) When customers return a product to a store and the store asks the customer to indicate the reason that the merchandise was returned, the resulting data are quantitative since multiple people will be providing the data. Answer: FALSE Keywords: data type, qualitative Section: 1-4 Data Types and Data Measurement Levels 80) Nominal data is the highest level of data. Answer: FALSE Keywords: measurement levels Section: 1-4 Data Types and Data Measurement Levels 81) At the end of the school term, students are asked to rate the course and instructor by indicating on a scale of 1-5 how well they liked the course. The data generated from this question are examples of ordinal data. Answer: TRUE Keywords: data type, ordinal Section: 1-4 Data Types and Data Measurement Levels 82) On a survey, amount of education is recorded as some high school, high school graduate, some college, college graduate, etc. This is an example of ordinal data. Answer: TRUE Keywords: measurement levels Section: 1-4 Data Types and Data Measurement Levels 83) A variable, i.e., the length of time it takes for an employee to complete an assembly procedure at an automotive plant, is a ratio level variable. Answer: TRUE Keywords: levels of measurement, ratio Section: 1-4 Data Types and Data Measurement Levels 84) A variable that has all the properties of an interval variable, but also has a true zero, is a ratio level variable. Answer: TRUE Keywords: levels of measurement, ratio Section: 1-4 Data Types and Data Measurement Levels 85) Cross-sectional data is a set of data values observed at successive points in time. Answer: FALSE Keywords: data type, time series Section: 1-4 Data Types and Data Measurement Levels 86) Data collected on marital status (married, divorced, single, other) would be an ordinal level variable. Answer: FALSE Keywords: data type, ordinal Section: 1-4 Data Types and Data Measurement Levels 87) Recently, a bank manager pulled a sample of customer accounts and recorded data for two variables, checking account balance and total number of transactions during the previous 30 days. The data collected would be considered time-series data. Answer: FALSE Keywords: data type, time series Section: 1-4 Data Types and Data Measurement Levels 88) Flavors of ice cream (chocolate, vanilla, strawberry, etc.) are an example of nominal data. Answer: TRUE Keywords: measurement levels Section: 1-4 Data Types and Data Measurement Levels 89) A major fast-food chain has installed a device that measures the temperature of the hamburgers on the grill. These data are stored in a computer file. If you were to analyze these data, you would be working with ordinal level data. Answer: TRUE Keywords: levels of measurement, ordinal Section: 1-4 Data Types and Data Measurement Levels 90) The difference between interval data and ratio data is that interval data has a natural zero. Answer: FALSE Keywords: measurement levels Section: 1-4 Data Types and Data Measurement Levels 91) If you have an ordinal variable, it is possible to precisely measure the magnitude of the difference between the possible values of the variable. Answer: FALSE Keywords: levels of measurement, ordinal Section: 1-4 Data Types and Data Measurement Levels 92) A cell phone service provider has 14,000 customers. Recently, the sales department selected a random sample of 400 customer accounts and recorded the number of minutes of long distance time used during the previous billing period. The data for this variable is considered to be nominal since the values are based on sample data. Answer: FALSE Keywords: levels of measurement, nominal Section: 1-4 Data Types and Data Measurement Levels 93) A cell phone service provider has 14,000 customers. Recently, the sales department selected a random sample of 400 customer accounts and recorded the number of minutes of long distance time used during the previous billing period. The company analyst used Excel to sort these values in order from high to low. She then assigned the highest value a rank of 1, the next highest value a rank of 2, and so forth. These ranks would be considered to be ordinal data. Answer: TRUE Keywords: levels of measurement, ordinal Section: 1-4 Data Types and Data Measurement Levels 94) A survey conducted by a local real estate agency asked respondents to indicate whether they preferred natural gas, electric, or oil furnaces for heating their home. The data collected for this variable would be of ordinal level. Answer: FALSE Keywords: levels of measurement, ordinal Section: 1-4 Data Types and Data Measurement Levels 95) A small engine repair shop tracks the number of customers who call each day. This variable is a time-series variable and also ratio level. Answer: TRUE Keywords: levels of measurement, time series, ratio Section: 1-4 Data Types and Data Measurement Levels 96) The use of charts and graphs is an example of: A) descriptive statistics. B) inferential statistics. C) estimation. D) hypothesis testing. Answer: A 97) When an administrator at a local hospital prepares a series of charts and graphs pertaining to the patients that have stayed at the hospital during the past month, she is using which general category of statistical analysis? A) Quantitative statistics B) Inferential statistics C) Descriptive statistics D) Random sampling Answer: C 98) Which of the following is an example of graphs used to describe data? A) Histograms B) Bar charts C) Both A and B are correct. D) None of the above. Answer: C , graphs 99) When a marketing manager surveys a few of the customers for the purpose of drawing a conclusion about the entire list of customers, she is applying: A) inferential statistics. B) descriptive statistics. C) quantitative models. D) numerical measures. Answer: A Keywords: inferential statistics 100) When the park ranger at Yellowstone National Park reports the average length of time that visitors spend in the park, he is using: A) graphical tools. B) numerical measures. C) statistical charts. D) histograms or bar charts. Answer: B 101) Recently, a major tire manufacturer stated in its advertising that its tires with a new tire tread design will last more than 50,000 miles on average. A consumer agency collected a subset of these tires and tested them in very controlled conditions. Based on this test, the agency concluded that the manufacturer was justified in making this claim. The process described is an example of: A) descriptive statistics. B) hypothesis testing. C) statistical inference. D) Both B and C are correct. Answer: D , inferential statistics, hypothesis testing 102) A consumer products company is considering introducing a new product nationally. To help make the decision, it first conducts a test market by selling the product for a few months in one city. This is an example of: A) descriptive statistics. B) charts and graphs. C) estimation. D) hypothesis testing. Answer: C Keywords: inferential statistics 103) The Biltmore Hotel manager is getting ready to make a presentation that she hopes will justify adding additional staff. As part of the presentation, she has constructed charts and graphs. The general type of statistical analysis she is using is: A) hypothesis testing. B) estimation. C) inferential statistics. D) descriptive statistics. Answer: D , graphs 104) Estimation and hypothesis testing are categories of: A) inferential statistics. B) descriptive statistics. C) numerical measurement. D) statistical charts. Answer: A Keywords: inferential statistics 105) A political poll that is used to indicate the percentage of voters who will vote for a particular candidate makes use of which of the following? A) Hypothesis testing B) Numerical analysis C) Estimation D) Both B and C Answer: D Keywords: inferential statistics 106) The company that makes a new weight loss pill claims that people who use this pill according to instructions will lose an average of 20 pounds during a four-month period. They say the claim is based on a study of 300 people. Which of the following statistical methods was most likely used to arrive at the company's conclusion? A) Estimation B) Hypothesis testing C) Histograms D) Bar charts Answer: B Keywords: inferential statistics 107) When the California Highway Patrol states that a study of drivers on a rural highway shows that the average speed is between 62.5 mph and 64.5 mph, they are most likely basing this statement on: A) descriptive statistics. B) estimation. C) hypothesis testing. D) graphical analysis. Answer: B Keywords: inferential statistics 108) The summaries of data, which may be in forms of tabular, graphical, or numerical, are referred to as: A) inferential statistics. B) descriptive statistics. C) statistical inference. D) report generation. Answer: B 109) Based on a survey of 400 students in a university in which 20 percent indicated that they were business majors. The university student newspaper reported that "20 percent of all the students at the university are business majors." This report is an example of: A) a sample. B) a population. C) statistical inference. D) descriptive statistics. Answer: C Keywords: inferential statistics 110) A company is interested in determining which of several advertising layouts is most effective at generating additional sales. The data collection tool that would most likely be used in this situation is: A) telephone survey. B) mail questionnaire. C) experiment. D) observation. Answer: C Keywords: data collection Section: 1-2 Procedures for Collecting Data 111) A company conducted a survey of its employees to determine their level of satisfaction with various company policies. The data collected from this survey are: A) primary data. B) secondary data. C) experimental data. D) census data. Answer: A Keywords: data collection, primary data Section: 1-2 Procedures for Collecting Data 112) The Dalton Company has recently made a decision to build a new plant in Denver. In making this decision it used data supplied by the U.S. Census Bureau. For the Dalton Company, these data are examples of: A) primary data. B) secondary data. C) reliable data. D) experimental data. Answer: B Keywords: data collection, secondary data Section: 1-2 Procedures for Collecting Data 113) An Internet service provider wants to determine its level of customer satisfaction. The best data collection method to obtain the results most quickly is: A) experiment. B) telephone survey. C) mailed survey. D) personal interview. Answer: B Keywords: data collection Section: 1-2 Procedures for Collecting Data 114) A tire manufacturing company is interested in obtaining data on stopping distances for each of the three main tread types made by the company. The data collection method that would be most likely used in this case would be: A) telephone survey. B) written questionnaire. C) demographic surveying. D) experiments. Answer: D Keywords: data collection, experimental Section: 1-2 Procedures for Collecting Data 115) Which of the following data collection methods is most likely to generate the largest nonresponse? A) Mail surveys B) Direct observation C) Telephone surveys D) Personal interviews Answer: A Keywords: data collection, mail surveys Section: 1-2 Procedures for Collecting Data 116) In developing and conducting a survey, what is the purpose of the pre-test phase? A) To make sure that the cost of developing the survey instrument is not too great B) To generate initial data for analysis C) To catch any problems with the questionnaire before it is fully administered D) To make sure that the respondents like the issues being addressed by the survey Answer: C Keywords: data collection, survey pre-test Section: 1-2 Procedures for Collecting Data 117) For which data collection method is it most important to have a polished-looking survey form? A) Telephone survey B) Written questionnaire C) Experimental design D) Personal interview Answer: B Keywords: data collection, questionnaire Section: 1-2 Procedures for Collecting Data 118) Which of the following types of questions provide the respondent with the greatest choice in responding to a question? A) Open-end questions B) Close-end questions C) Multiple choice questions D) True/false questions Answer: A Keywords: data collection, open-ended Section: 1-2 Procedures for Collecting Data 119) A consumer products company wants to interview customers regarding a new product. If it wishes to adhere to a predetermined pattern of questions in the interview, which of the following would likely be used? A) Structured interview B) Open-end questioning C) Unstructured interview D) Written questionnaire Answer: A Keywords: data collection, structured interview Section: 1-2 Procedures for Collecting Data 120) In conducting a personal interview, what problem can result if the interviewer is allowed to arbitrarily decide who should be interviewed? A) Nonresponses B) Missing data C) Bias D) Poor response rate Answer: C Keywords: data collection, bias Section: 1-2 Procedures for Collecting Data 121) One of the major challenges for developing a good written questionnaire or telephone survey instrument is that: A) nonresponses are too high. B) there will always be missed data. C) bias cannot be controlled. D) wording can influence responses. Answer: D Keywords: data collection Section: 1-2 Procedures for Collecting Data 122) When an accounting auditor randomly selects 20 accounts from all the accounts to check for accuracy, she has selected: A) a personal observation. B) a sample from the population. C) a census. D) a convenience sample. Answer: B Keywords: data collection, sample Section: 1-3 Populations, Samples and Sampling Techniques 123) An Internet service provider has the capability of tracking the time that each of its customers spends connected to the Internet during a month. These data would constitute: A) a simple random sample. B) a convenience sample. C) a cluster sample. D) a population. Answer: D Keywords: data collection, population Section: 1-3 Populations, Samples and Sampling Techniques 124) A professor hands out survey forms during her classes, where the population is all students attending the college. This is an example of: A) a convenience sample. B) a simple random sample. C) a stratified sample. D) a cluster sample. Answer: A Keywords: convenience sampling Section: 1-3 Populations, Samples and Sampling Techniques 125) Another term used for statistical sampling is: A) probability sampling. B) convenience sampling. C) ratio sampling. D) numerical sampling. Answer: A Keywords: probability sample Section: 1-3 Populations, Samples and Sampling Techniques 126) A grocery store is interested in determining whether its customers are satisfied with the quality of service provided. To collect the necessary data, interviewers have been hired to stand near the store's exits and to survey customers who have the time and interest to be surveyed. This type of sampling is called: A) systematic random sampling. B) ratio sampling. C) convenience sampling. D) stratified sampling. Answer: C Keywords: convenience sampling Section: 1-3 Populations, Samples and Sampling Techniques 127) The Polson Pole and Fence Company recently did a quality check on the length of fence posts. To do this, each of the 400 posts in inventory was numbered. Numbers from 1 to 400 were placed in a bowl. Twenty numbers were selected from the bowl without looking. These 20 poles were the ones selected for the study. This type of sampling is called: A) cluster sampling. B) simple random sampling. C) nonstatistical. D) convenience sampling. Answer: B Keywords: simple random samples Section: 1-3 Populations, Samples and Sampling Techniques 128) In order to determine a parameter (such as a mean) of a population you would need to conduct a: A) population. B) random sample. C) census. D) statistic. Answer: C Keywords: population, parameter Section: 1-3 Populations, Samples and Sampling Techniques 129) If a systematic random sample is to be selected of size 100 from a population with 5,000 items, the first item selected from the ordered population will be: A) randomly selected between 1 and 100. B) randomly selected between 1 and 50. C) any randomly selected value between 1 and 5,000. D) item 50. Answer: B Keywords: systematic sample Section: 1-3 Populations, Samples and Sampling Techniques 130) If a stratified random sample is to be conducted, which of the following is true? A) The population will be broken down into subgroups called strata. B) Each subgroup should contain items that are homogeneous with respect to the characteristic of interest. C) If effective, the total required sample size should be less than that which would be needed if a simple random sample were selected. D) All of the above. Answer: D Keywords: stratified sample Section: 1-3 Populations, Samples and Sampling Techniques 131) A food warehouse manager plans to conduct a check on damaged packages. The warehouse covers a large area and products are spread out over the entire building. Assuming that no products are more likely to have damaged packages than any other, what statistical sampling method would be used to reduce the time and effort required to do the study? A) Convenience sampling B) Stratified random sampling C) Cluster random sampling D) Systematic random sampling Answer: C Keywords: cluster sample Section: 1-3 Populations, Samples and Sampling Techniques 132) Some stores and restaurants have "tell us what you think" cards available for customers. Assuming that angry customers are more likely to take the time to fill these out, this is an example of: A) simple random sampling. B) stratified sampling. C) cluster sampling. D) nonstatistical sampling. Answer: D Keywords: sampling methods Section: 1-3 Populations, Samples and Sampling Techniques 133) The mayor of a large U.S. city is interested in addressing complaints from many property owners regarding recent property assessments. Many people feel that they are being overtaxed and that their assessments are too high. To study this issue, the mayor plans to hire consultants to randomly select homes in the city and have these homes independently assessed for value. However, she is concerned that the cost of sampling will be very high since the city is spread out over a wide geographical area. To potentially reduce the cost of sampling, which of the following statistical sampling techniques should be applied? A) Cluster sampling B) Ratio sampling C) Simple random sampling D) Stratified random sampling Answer: A Keywords: sampling methods Section: 1-3 Populations, Samples and Sampling Techniques 134) The human resources department at a major high tech company plans to conduct an employee satisfaction study by sampling 100 employees from the 3,000 total employees. They plan to use systematic random sampling since the employee file is in alphabetic order. The first employee selected in the study should be: A) the 30th employee. B) employee 1 to 30 randomly selected. C) employee 1 to 100 randomly selected. D) the first employee. Answer: B Keywords: systematic random sample Section: 1-3 Populations, Samples and Sampling Techniques 135) A value computed from a population is called: A) a statistic. B) a real number. C) a parameter. D) a point estimate. Answer: C Keywords: statistic Section: 1-3 Populations, Samples and Sampling Techniques 136) Which of the following statements is true? A) Random samples are easier to select than nonstatistical samples. B) Nonstatistical samples can provide useful data. C) Stratified random sampling involves breaking the population down into geographic subgroups. D) Systematic sampling is an example of nonstatistical sampling. Answer: B Keywords: nonstatistical sampling Section: 1-3 Populations, Samples and Sampling Techniques 137) In Excel, what procedure is used to select random numbers? A) The random numbers function B) Click on the Data tab, then click on Data Analysis, then click on Sampling C) Click on the Data tab, then click on Data Analysis, then click on Random Number Generation D) Random numbers are not available in Excel. Answer: C Keywords: Excel, random number generation Section: 1-3 Populations, Samples and Sampling Techniques 138) A sampling plan that requires a person to interview 100 people as they exit a department store would most likely be: A) a simple random sample. B) a convenience sample. C) a systematic random sample. D) a stratified sample. Answer: B Keywords: convenience samples Section: 1-3 Populations, Samples and Sampling Techniques 139) Which one of the following is NOT statistical sampling? A) Simple random sample B) Stratified random sampling C) Cluster sampling D) Convenience sampling Answer: D Keywords: statistical and nonstatistical sampling Section: 1-3 Populations, Samples and Sampling Techniques 140) When a survey uses the responses strongly disagree, disagree, neutral, agree, strongly agree, this is an example of: A) nominal data. B) ordinal data. C) interval data. D) ratio data. Answer: B Keywords: measurement levels Section: 1-4 Data Types and Data Measurement Levels 141) General Electric Corporation tracks employee turnover annually. It currently has a data set that contains turnover for the past 20 years. What type of data does it have? A) Time-series data B) Cross-sectional data C) Nominal data D) Ordinal data Answer: A Keywords: data types, time series Section: 1-4 Data Types and Data Measurement Levels 142) The human resources department at a major high tech company recently conducted an employee satisfaction survey of 100 of its 3,000 employees. Data were collected on such variables as age, gender, marital status, current salary, level of overall satisfaction on a scale from 1 to 5, number of years with the company, and job title. Which of the following best describes the overall data set that was generated from the study? A) Cross-sectional data B) Time-series data C) Nominal data D) Quantitative data Answer: A Keywords: data types, cross-sectional Section: 1-4 Data Types and Data Measurement Levels 143) The human resources department at a major high tech company recently conducted an employee satisfaction survey of 100 of its 3,000 employees. Data were collected on such variables as age, gender, marital status, current salary, level of overall satisfaction on a scale from 1 to 5, number of years with the company, and job title. Considering the age variable where employees were asked to list their age at their last birthday, which of the following best describes the level of data measurement for that variable? A) Interval level B) Nominal level C) Ratio level D) Cross-sectional data Answer: C Keywords: data measurement levels, ratio Section: 1-4 Data Types and Data Measurement Levels 144) The high temperature is recorded each day for a period of 1 year. This is an example of: A) nominal data. B) ordinal data. C) time-series data. D) cross-sectional data. Answer: C Keywords: data type, time series Section: 1-4 Data Types and Data Measurement Levels 145) The human resources department at a major high tech company recently conducted an employee satisfaction survey of 100 of its 3000 employees. Data were collected on such variables as age, gender, marital status, current salary, level of overall satisfaction on a scale from 1 to 5, number of years with the company, and job title. Which of the variables listed are considered to be ratio level data? A) Age and years with the company B) Gender and marital status C) Job title D) None of the variables is ratio level. Answer: A Keywords: data measurement levels, ratio Section: 1-4 Data Types and Data Measurement Levels 146) The human resources department at a major high tech company recently conducted an employee satisfaction survey of 100 of its 3,000 employees. Data were collected on such variables as age, gender, marital status, current salary, level of overall satisfaction on a scale from 1 to 5, number of years with the company, and job title. Which of the variables would be classified as nominal level data? A) Age and years with the company B) Overall satisfaction C) Gender, marital status, and job title D) Age and gender Answer: C Keywords: data measurement levels, nominal Section: 1-4 Data Types and Data Measurement Levels 147) The human resources department at a major high tech company recently conducted an employee satisfaction survey of 100 of its 3,000 employees. Data were collected on such variables as age, gender, marital status, current salary, level of overall satisfaction on a scale from 1 to 5, number of years with the company, and job title. Which of the variables would be considered to be qualitative data? A) Gender, marital status, job satisfaction, and job title B) Age C) Years with the company D) All variables listed are qualitative. Answer: A Keywords: data types, qualitative data Section: 1-4 Data Types and Data Measurement Levels 148) Weekly stock closing prices for IBM would be classified as which of the following? A) Cross-sectional data B) Time-series data C) Nominal data D) Ordinal data Answer: B Keywords: data types, time series Section: 1-4 Data Types and Data Measurement Levels 149) A college data base includes the number of people who are enrolled in each class the college offers. This is an example of: A) nominal data. B) ordinal data. C) interval data. D) ratio data. Answer: D Keywords: measurement levels Section: 1-4 Data Types and Data Measurement Levels 150) When data are organized into levels, the highest data level is: A) interval level data. B) nominal level data. C) ordinal level data. D) ratio level data. Answer: D Keywords: data measurement levels, ratio Section: 1-4 Data Types and Data Measurement Levels 151) Data collected at a fixed point in time are: A) time-series data. B) approximate time-series data. C) cross-sectional data. D) panel data. Answer: C Keywords: time-series data, cross-sectional data Section: 1-4 Data Types and Data Measurement Levels 152) What is meant by the term statistical inference? Answer: A statistical inference is a conclusion reached about a population value (parameter) based upon an analysis of data in a statistical sample from the population. The idea is that we can study the sample data and then draw a conclusion (inference) about what the entire population looks like with respect to the measure of interest. There are two main categories of statistical inference: estimation and hypothesis testing. Keywords: inferential statistics 153) Discuss the differences and similarities between statistical estimation and statistical hypothesis testing. Answer: Both estimation and hypothesis testing fall under the main category of statistical procedures called inferential statistics. In both cases, we are attempting to better understand the population of interest by examining the data in a sample from the population. With estimation, we begin with a goal of estimating a population value such as a population mean. We don't have a preconception about what that value is. Instead, we look at a corresponding value for the sample (i.e., sample mean) and use that as our "best" guide to what the population value is. With hypothesis testing, we begin with a claim or idea (hypothesis) about what the population value is and then we use the corresponding sample value to either support or refute the claim or idea. Keywords: inferential statistics 154) Explain what an experimental design is. Answer: When an experiment is conducted with an experimental design the factors that may affect the variable of interest are controlled so their effect can be observed. Each factor has several predefined levels and the combinations of the various factor levels are tested. Keywords: data collection, experimental design Section: 1-2 Procedures for Collecting Data 155) Discuss the steps involved in developing and carrying out a written survey. Answer: While there are several possible approaches to developing and conducting a written survey, there are several steps that most approaches would include. These are: Define the issue — You need a clear understanding of what it is that you wish to learn from the survey. Define the population of interest — You must determine who the people are that are to be surveyed. You need to be specific about this since those surveyed will hopefully represent the views of the entire population. Design the survey instrument — You need to develop the questions that will get at the answers to your research questions. A written survey must be a reasonable length and the questions need to be well-written and clear. You need to be careful not to interject bias in the way the question is written. The survey design should be clear and easy for the respondents to use. Pre-test — You should always pre-test the survey with a small subgroup from the population. Use their feedback to make constructive improvements in the survey and to make sure that you have included the right questions given your original objective. Determine the sample size and sampling method — Whenever possible you want to survey a large number of people, but your sampling budget will limit you. It will be necessary to determine how many are needed for statistical validity and for meeting objectives. You also need to specify how the sample is to be selected from the population—statistical or nonstatistical—and specifically what sampling method to use. Select the sample and administer the survey — The survey can be administered in several ways—through the mail, on the Internet, or in person. Keywords: data collection, survey Section: 1-2 Procedures for Collecting Data 156) What are the advantages and disadvantages of open-end questions in either a written survey or a personal interview? Answer: Open-end questions allow the respondent to provide a broad range of input and not be restricted to a defined set of response options. This is an advantage since it is possible to tap into the true feelings of the respondent and to obtain responses that might not have been anticipated when the survey was developed. The disadvantage is that analysis of the responses to open-end questions is difficult. The analyst must somehow code the potentially broad range of responses into categories. This takes time and often requires interpretation that might interject bias into the analysis. Keywords: data collection, survey, interview Section: 1-2 Procedures for Collecting Data 157) Discuss the two major types of descriptive statistics. Answer: Descriptive statistics includes methods for summarizing a data set. The two major types of descriptive statistics are (1) charts and graphs, and (2) summary numerical measures. Charts and graphs include "picture" type tools such as histograms, bar charts and pie charts that visually summarize a data set. Numerical summary measures are numbers such as the average that describe a characteristic of the data set. 158) Is there ever a reason why we might prefer to work with a sample rather than with an entire population? Discuss. Answer: A sample is a subset of a population and might not be a perfect representation of the population. As a result, it is possible that when our objective is to know characteristics of the population, the values we get from the sample might be misleading. Thus, in the general case, we would prefer to have access to all the data in the population. However, there are reasons why we might be better off with a sample in some instances. For example, if the population is very large, the time and cost of collecting data from the entire population might make the project unfeasible. In addition, when a great number of measurements are required for a large population, measurement and/or coding errors could be introduced that would give us incorrect information about the population. In addition, if the measurement process requires that we destroy, or otherwise modify, the population values, it would not make sense to deal with the entire population. In these cases, a sample might well be preferable to a census of the population. Keywords: sample, population Section: 1-3 Populations, Samples and Sampling Techniques 159) What is the underlying common element of all statistical sampling techniques? Answer: The basis for all statistical sampling techniques is that the items selected in the sample are chosen at random from the population. This provides the potential to perform an objective analysis of the data and reach objective conclusions about the population based on the sample. Keywords: random sampling Section: 1-3 Populations, Samples and Sampling Techniques 160) Explain the difference between stratified random sampling and cluster random sampling. Answer: Both techniques are considered statistical sampling techniques since the elements to be included in the sample are randomly selected. Likewise, both techniques have as their objective reducing the cost of sampling as compared to a simple random sample. However, the two techniques are fundamentally different. With stratified random sampling, the population is divided into homogeneous subgroups (strata) with the intent of having the elements in a particular subgroup be as much alike as possible, thereby making it possible to know about all items in the subgroup by examining only a few of the subgroup items. Thus, the overall sample size, which is the sum of the samples from each stratum, could be smaller than the sample size needed if the sampling was done using a simple random sampling approach. Cluster sampling is used when the population values are spread out over a relatively wide geographical area and data collection would be costly due to movement among the population values. With cluster sampling, the population is divided into groups called clusters that are usually defined by geographical boundaries. Each cluster is intended to be as heterogeneous as the population as a whole. Then a random selection of clusters is selected and the sampled items are all selected from only those clusters. This potentially reduces the travel costs. Keywords: sampling methods, stratified, cluster Section: 1-3 Populations, Samples and Sampling Techniques 161) Open the data file provided with the text called AirlinePassengers. Indicate the level of data measurement for each variable in the data set. Answer: Airline - nominal Day of Week - ordinal Time of Day - nominal Male/Female - nominal Business/Pleasure - nominal Length of Trip- - ordinal Hours to Destination - ratio Children < 10 years - nominal Pieces of Luggage - ratio Pieces Carried On - ratio Times Flown - ratio Keywords: data measurement levels Section: 1-4 Data Types and Data Measurement Levels 162) Open the data file provided with the text called Computer Use. Indicate the level of data measurement for each variable in the data set. Answer: Major - nominal Comp. Use - ordinal Comp. Hours - ratio Labs - ordinal Benefit - nominal Higher Tuition - nominal Enrollment Decision - nominal Price to Pay - ratio Keywords: data measurement levels Section: 1-4 Data Types and Data Measurement Levels 163) Of the following techniques for collecting data, which one is generally considered the least costly to implement: experiments, telephone surveys, mail questionnaires, direct observation, personal interview? Answer: In most instances, the mail questionnaire is the least costly method for data collection. Even though response rates are notoriously low, the cost of sending surveys in the mail is very low on a per item basis. However, there are many instances where mail surveys can't be used to collect the required data. For instance, if we are interested in the impact of greater drying heat in the press when plywood is manufactured, we can't very well send a survey to a piece of plywood asking for information about its strength and quality! An experiment would be required. In other instances, we need to use observation to get accurate data since people might be tempted to reply with the desired response rather than the truth. For instance, a question like, "Do you wear your seatbelt when driving in your car?" might not provide accurate data in a written survey. Observation might provide better data on driver behavior. Keywords: data collection Section: 1-2 Procedures for Collecting Data 164) What are the major categories of statistical tools that will be covered in this course? Answer: Business statistics can be divided into two main categories: descriptive statistics and inferential statistics. Probability is a link between the two and is a major part of the statistical inference section. Keywords: descriptive, inferential statistics 165) In a survey, what is meant by demographic questions and why might we want to include demographic questions in survey? Answer: Demographic questions are questions that pertain to the respondent such as age, gender, education level, etc. The purpose of demographic questions is to be able to group responses to the central survey questions by category of the demographic questions. For instance, we might group responses to a question about product satisfaction by male/female to see whether males and females have different views about the product. Keywords: data collection, demographics Section: 1-2 Procedures for Collecting Data 166) As a member of the student council at your university, you have been assigned the task of conducting a phone survey of undergraduate students to determine satisfaction with the campus food service. Explain how you would go about selecting a simple random sample. Answer: We need to obtain a frame (list) of the population that might be available through the registrar's office. We would assign each student a number from 1 through the number of students. Assuming that this list contains a contact phone number for each student, we could select a simple random sample by using Excel (or a random numbers table) to select the desired sample size. We would probably select extra students since some would be unreachable or not use campus food service. We should establish a call-back procedure to reduce sampling bias. Keywords: simple, random, sample, bias Section: 1-3 Populations, Samples and Sampling Techniques 167) Explain the difference between a stratified random sample and cluster random sample. Answer: First, both sampling techniques are examples of statistical sampling procedures. However, they are very different in purpose. In stratified random sampling, the population is broken down into homogeneous groups called strata. The idea is that the elements in each strata are as much alike as possible so that the required sample size from each strata is reduced. Then the total sample size selected from all strata will hopefully be less than the required sample size that would be needed if stratification were not used. In cluster sampling, the population is divided into geographical subgroups. The hope is that each subgroup is a mirror image of the population as a whole. Then a few of the clusters are randomly selected and all sampling of individual items is taken from only the selected clusters. The objective is to reduce the cost of sampling by reducing the physical area that must be covered in the sample. Keywords: stratified, random, cluster, sample Section: 1-3 Populations, Samples and Sampling Techniques The Where, Why, and How of Data Collection Section 1.1 1.1 This application is primarily descriptive in nature. The owner wishes to develop a presentation. She will most likely use charts, graphs, tables and numerical measures to describe her data. 1.2 The graph is a bar chart. A bar chart displays values associated with categories. In this case the categories are the departments at the food store. The values are the total monthly sales (in dollars) in each department. A bar chart also typically has gaps between the bars. A histogram has no gaps and the horizontal axis represents the possible values for a numerical variable. 1.3 A bar chart is used whenever you want to display data that has already been categorized while a histogram is used to display data over a range of values for the factor under consideration. Another fundamental difference is that there typically are gaps between the bars on a bar chart but there are no gaps between the bars of a histogram. 1.4 Businesses often make claims about their products that can be tested using hypothesis testing. For example, it is not enough for a pharmaceutical company to claim that its new drug is effective in treating a disease. In order for the drug to be approved by the Food and Drug Administration the company must present sufficient evidence that the drug first does no harm and that it also provides an effective treatment against the disease. The claims that the drug does no harm and is an effective treatment can be tested using hypothesis testing. 1.5 Hypothesis testing uses statistical techniques to validate a claim. With hypothesis testing, sample data is used to make an inference about the larger population from which the sample was drawn. Student-provided examples will differ depending on their experiences. 1.6 Statistical inference procedures are useful in situations where a decision maker needs to reach an estimate about a population based on a subset of data taken from the population. For example, a decision maker might want to know the starting annual salary of all attorneys in the United States. If it is not feasible or possible to look at the salary data for all attorneys, the decision maker could look at a subset of attorneys and use statistical inference to reach a conclusion about the population of all attorneys. 1.7 Hypothesis testing is used whenever one is interested in testing claims that concern a population. Using information taken from samples, hypothesis testing evaluates the claim and makes a conclusion about the population from which the sample was taken. Estimation is used when we are interested in knowing something about all the data, but the population is too large, or the data set is too big for us to work with all the data. In estimation, no claim is being made or tested. 1.8 The major advantage of a graph is it allows a more complete representation of information in the data. Not only can a decision maker visualize the center of the data but also how spread out the data is. An average, for instance, nicely represents the center of a data set, but contains no information of how spread out the data is. 1.9 By its nature, a single measure is just one value and therefore is simpler than a table. It allows an easy method of comparison between two or more data sets, something that is more difficult if the data sets are represented in tabular form. In addition, although not mentioned in this chapter, additional statistical techniques, such as hypothesis testing and estimation, involve calculations based on a single measure from a subset of population data. 1.10 The company could use statistical inference to determine if its parts last longer. Because it is not possible to examine every part that could be produced the company could examine a randomly chosen subset of its parts and compare the average life of the subset to the average life of a randomly chosen subset of the competitor’s parts. By using statistical inference procedures the company could reach a conclusion about whether its parts last longer or not. 1.11 Student answers will vary depending on the periodical selected and the periodical's issue date, but should all address the three parts of the question. 1.12 The appropriate chart in this case is a histogram where the horizontal axis contains the number of missed days and the area of the bars represent the number of employees who missed each number of days. Note, there are no gaps between the bars. 1.13 Because it would be too costly, too time consuming, or practically impossible to contact every subscriber to ascertain the desired information, the decision makers at Fortune might decide to use statistical inference, particularly estimation, to answer its questions. By looking at a subset of the data and using the procedures of estimation it would be possible for the decision makers to arrive at values for average age and average income that are within tolerable limits of the actual values.. 1.14 Student answers will vary depending on the business periodical or newspaper selected and the article referenced. Some representative examples might include estimates of the number of CEO's who will vote for a particular candidate, estimates of the percentage increase in wages for factory workers, estimates of the average dollar advertising expenditures for pharmaceutical companies in a specific year, and the expected increase in R&D expenditures for the coming quarter. 1.15. Student answers will vary. However, the examples should illustrate how statistics has been used and should clearly indicate the type of statistical analysis employed. 1.16 A commonly used measure of the center of the data is the mean or average. The executive could calculate the average age of the people in the market area and use the average as the center value. To determine a value for the percentage of people in the market area that are senior citizens, the executives would rely on estimation--a set of statistical techniques that allow one to know something about a data set by using a subset of the data whenever the data set is too large to work with all the data. The executives might want to test the hypothesis that the percentage of senior citizens in the market area is greater than the percentage of senior citizens nationwide. The executives could also test the hypothesis that the percentage of senior citizens is greater than or less than a specific value, say 27%. Section 1.2 1.17 As discussed in this section, the pet store would most likely use a written survey or a telephone survey to collect the customer satisfaction data. 1.18 A leading question is one that is designed to elicit a specific response, or one that might influence the respondent’s answer by its wording. The question is posed so that the respondent believes the researcher has a specific answer in mind when the question is asked, or worded in such a way that the respondent feels obliged to provide an answer consistent with the question. For example, a question such as “Do you agree with the experts who recommend that more tax dollars be given to clean up dangerous and unhealthy pollution?” could cause respondents to provide the answer that they think will be consistent with the “experts” with whom they do not want to disagree. Leading question should be avoided in surveys because they may introduce bias. 1.19 An experiment is any process that generates data as its outcome. The plan for performing the experiment in which the variable of interest is defined is referred to as an experimental design. In the experimental design one or more factors are identified to be changed so that the impact on the variable of interest can be observed or measured. 1.20 In a survey, poorly worded and leading questions can produce different results. Major organizations usually do a good job of conducting surveys. However, sometimes even seemingly subtle differences in wording can lead to different outcomes. Here the noticeable difference in the three surveys is that one mentions tax payers and the other two the government or government agencies. While this may seem a minor difference, it could be significant enough to cause the difference in response. 1.21. There will likely by a high rate of nonresponse bias since many people who work days will not be home during the 9-11 AM time slot. Also, the data collectors need to be careful where they get the phone number list as some people do not have listed phones in phone books and others have no phone or only a cell phone. This may result in selection bias. 1.22 Observation would be the most likely method. Observers could be located at various bike routes and observe the number of riders with and without helmets. This would likely be better than asking people if they wear a helmet since the popular response might be to say yes even when they don’t always do so. A telephone survey to gas stations in the state. This could be a cost effective way of getting data from across the state. The respondent would have the information and be able to provide the correct price. A written survey of passengers. This could be given out on the plane before the plane lands and passengers could drop the surveys in a box as they de-plane. This method would likely garner higher response rates compared to sending the survey to passengers’ mailing address and asking them to return the completed survey by mail. 1.23 The two types of validity mentioned in the section are internal validity and external validity. For this problem external validity is easiest to address. It simply means the sampling method chosen will be sufficient to insure the results based on the sample will be able to be generalized to the population of all students. Internal validity would involve making sure the data gathering method, for instance a questionnaire, accurately determines the respondent’s attitude toward the registration process. 1.24 This data could have been collected through observation or experiment. Employees of the USDA could provide periodic reports of fire ant activity in their region. Likewise, scientists studying the spread of fire ants may have conducted experiments that indicate the rate of spread under certain conditions. 1.25 There are many potential sources of bias associated with data collection. If data is to be collected using personal interviews it will be important that the interviewer be trained so that interviewer bias, arising from the way survey questions are asked, is not injected into the survey. If the survey is conducted using either a mail survey or a telephone survey then it is important to be aware of nonresponse bias from those who do not respond to the mailing or refuse to answer your calls. You must also be careful when selecting your survey subjects so that selection bias is not a problem. In order to have useful, reliable data that is representative of the true student opinions regarding campus food service, it is necessary that the data collection process be conducted in a manner that reduces or eliminates the potential for these and other sources of potential bias. 1.26 For retailers technology that scans the product UPC code at checkout makes the collection of data fast and accurate. Retailers that use such technology can automatically update their inventory records and develop an extensive collection of customer buying habits. By applying advanced statistical techniques to the data the retailer can identify relationships among purchases that might otherwise go unnoticed. Such information could enable retailers to target their advertising or even rearrange the placement of products in the store to increase sales. Manufacturing firms use bar code scanning to collect information concerning product availability and product quality. Credit card purchases are automatically tracked by the retailer and the bankcard company. In this way the credit card company is able to track your purchases and even alert you to potential fraud if purchases on your card appear to be unusual. Finally, some companies are using radio frequency identification (RFID) to track products through their supply chain, so that product delays and inventory problems can be minimized. 1.27 One advantage of this form of data gathering is the same as for mail questionnaires. That is low cost. Additional factors being speed of delivery and, with current software, with closed- ended questions, instant updating of data analysis. Disadvantages are also similar, in particular low response and potential confusion about questions. An additional factor might be the ability of competitors to “hack” into the database and analysis program. 1.28. Student answers will vary. Look for clarity of questions and to see that the issue questions are designed to gather useful data. Look for appropriate demographic questions. 1.29 Students should select some form of personal observation as the data-gathering technique. In addition, there should be a discussion of a sampling procedure with an effort made to ensure the sample randomly selected both days of the week unless daily observations are made, and randomly selected times of the day since 24 hour observation would likely be impossible. A complete answer would also address efforts to reduce the potential bias of having an observer standing in an obvious manner by the displays. 1.30 Student answers will vary. However, the issue questions should be designed to gather the desired data regarding customers’ preferences for the use of the space. Demographic questions should provide data so that the responses can be broken down appropriately so that United Fitness Center managers can determine which subset of customers have what opinion about this issue. Regarding questionnaire layout, look at neatness and answer location space. Make sure questions are properly worded, used reasonable vocabulary, and are not leading questions. 1.31 The results of the survey are based on telephone interviews with 1,025 national adults, aged 18 and older. Students may also answer that the survey could have been conducted using personal interviews. Because telephone interviews were used to collect the survey data nonresponse biases associated with sampled adults who are not at home when phoned, or adults who refuse to participate in the survey. There is also the problem that some adults do not have a phone. If personal interviews are used to collect the data then it is important to guard against nonresponse bias from those sampled adults who refuse to be interviewed. There is also the problem of selection bias. In phone interviews we may miss the people who work evenings and nights. If personal interviews are used we must be careful to select a representative sample of the adult population, not just those who appear willing or interested in participating. Section 1.3 1.32. Because the population is spread over a large geographical area, a cluster random sample could be selected to reduce travel costs. A stratified random sample would probably be used to keep sample size as small as possible. Most likely a convenience sample would be used since doing a statistical sample would be too difficult. 1.33 To determine the range of employee numbers for the first employee selected in a systematic random sample use the following: Part range = Thus, the first person selected will come from employees 1-180. Once that person is randomly selected, the second person will be the one numbered 100 higher than the first, and so on. 1.34 Whenever a descriptive numerical measure such as an average is calculated from the entire population it is a parameter. The corresponding measure calculated from a subset of the population, that is to say a sample, is a statistic. 1.35 Statistical sampling techniques consist of those sampling methods that select samples based on chance. Nonstatistical sampling techniques consist of those methods of selecting samples using convenience, judgment, or other nonchance processes. In convenience sampling, samples are chosen because they are easy or convenient to sample. There is no attempt to randomize the selection of the selected items. In convenience sampling not every item in the population has a random chance of being selected. Rather, items are sampled based on their convenience alone. Thus, convenience sampling is not a statistical sampling method. 1.36 From a numbered list of all customers who own a certificate of deposit the bank would need to randomly determine a starting point between 1 and k, where k would be equal to 25000/1000 = 25. This could be done using a random number table or by having a statistical package or a spreadsheet generate a random number between 1 and 25. Once this value is determined the bank would select that numbered customer as the first sampled customer and then select every 25th customer after that until 100 customers are sampled. 1.37 A census is an enumeration of the entire set of measurements taken from the population as a whole. While in some cases, the items of interest are obtained from people such as through a survey, in many instances the items of interest come from a product or other inanimate object. For example, a study could be conducted to determine the defect rate for items made on a production line. The census would consist of all items produced on the line in a defined period of time. 1.38 Values computed from a sample are always considered statistics. In order for a value, such as an average, to be considered a parameter it must be computed from all items in the population. 1.39 In stratified random sampling, the population is divided into homogeneous groups called strata. The idea is to make all items in a stratum as much alike as possible with respect to the variable of interest thereby reducing the number of items that will need to be sampled from each stratum. In cluster sampling, the idea is to break the population into heterogeneous groups called clusters (usually on a geographical basis) such that each cluster looks as much like the original population as possible. Then clusters are randomly selected and from the cluster, individual items are selected using a statistical sampling method. 1.40 Using Excel, choose the Data tab, select Data Analysis from the Analysis Group , then Random Number Generation – shown as follows: The next step is to complete the random number generation dialog as follows: 199453530416500The resulting random numbers generated are: Note, the students’ answers may differ since Excel generates different streams of random numbers each time it is used. Also, if the application requires integer numbers, the Decrease Decimal option can be used. 1.41 If these percentages were based on all students attending college in those years they would would be parameters, if the percentages were based on a sample they would be statistics. 1.42 This is a statistic. A poll would be a sample of eligible voters rather than all eligible voters. 1.43 Solution a. Stratified random sampling b. Simple random sampling or possibly cluster random sampling c. Systematic random sampling d. Stratified random sampling 1.44 This is a statistical sample. Every employee has an equal chance of being selected using this method. In fact, this is an example of a simple random sample because every possible sample of size 50 has an equal chance of being selected. 1.45 Student answers will vary Cluster sampling could be used to ensure that you get all types of cereal. Make each cluster the area where certain cereals are located (i.e., isle, row, shelf, etc.) Cluster sampling would give you a better idea of the inventory of all types of cereal. Simple random sampling could possibly end up with only looking at 2 or 3 cereal types. 1.46 Students should choose the Data tab, select Data Analysis from the Analysis group – Random Number Generation process. Students’ answers will differ since Excel generates different streams of random numbers each time it is used, but 40 random numbers should be generated from a uniform distribution with values ranging from 1 to 578. Since the application requires integer numbers, the Decrease Decimal option should be used. 1.47 The population should be all users of cross-country ski lots and trailheads in Colorado. Several sampling techniques could be selected. Be sure that some method of ensuring randomness is discussed. In addition, some students might give greater weight to frequent users of the lots. In which case the population would really be user days rather than individual users. Students using Excel should choose the Data tab, select Data Analysis from the Analysis group – Random Number Generation process. Students’ answers may differ since Excel generates different streams of random numbers each time it is used. Since the application requires integer numbers, the Decrease Decimal option should be used. 1.48 Since there are 4,000 patient files we could give each file a unique identification number consisting of 4 digits. The first file would be given the identification number “0001”. The last file would be given the identification number of “4000”. By assigning each patient a number and randomly selecting the 100 numbers allows each possible sample of 100 an equal chance of being selected. Either use a random number table (randomly select the starting row and column), or use a computer program, such as Microsoft Excel or Minitab, which has a random number generator. Since each patient is assigned a 4-digit identification number, we would need a 4-digit random number for each random number selected. Answers will vary. Section 1.4 1.49. a. Time-series b. Cross-sectional c. Time-series d. Cross-sectional 1.50 Qualitative data are categories or numerical values that represent categories. Quantitative data is data that is purely numerical. 1.51 a. Ordinal – categories with defined order b. Nominal – categories with no defined order c. Ratio d. Nominal – categories with no defined order 1.52 Nominal data involves placing observations in separate categories according to some measurable characteristic. Ordinal data also involves placing observations into separate categories, but the categories can be rank-ordered. 1.53 Since the circles involve a ranking from best to worst, this would be ordinal data. 1.54 The data are cross-sectional. The data are collected from 2,300 customers at approximately the same point in time This is a ratio level, quantitative variable. The data represent a measurement of time. Ordinal with a numerical value representing customers rating of level of service 1.55 Nominal Data Ratio Data Nominal Data Ratio Data Ratio Data Nominal Data Ratio Data 1.56 Cross-sectional Time-series Cross-sectional Cross-sectional Time-Series 1.57 Brand - Nominal Model – Nominal Sports Car – Nominal SUV – Nominal Wagon – Nominal Minivan – Nominal Pickup – Nominal All-Wheel Drive – Nominal Rear-Wheel Drive – Nominal Suggested Retail Price – Ratio Dealer Cost – Ratio Engine Size – Ratio Cylinders – Ratio Horsepower – Ratio City MPG – Ratio Highway MPG – Ratio Weight – Ratio Wheel base – Ratio Length - Ratio Width - Ratio 1.58. a. The data are cross-sectional since they represent data across a sample of customers where the data reflect the demographics of the customers at basically one point in time. b. The following variables are quantitative: Past Due Amount Current Amount Due The following variables are qualitative: Account number Caller gender Account Holder gender Was this a billing question? Even though these variables have numeric values, because the numbers represent a discrete category, they are considered qualitative. c. The following variables are ratio level measures: Past Due Amount Current Amount Due The following variables are nominal measures: Account number Caller gender Account Holder gender Was this a billing question? End of Chapter 1.59 Answers will vary with the student. But a good discussion should include the following factors: Sampling techniques and possible problems selecting a representative sample. Determining how to develop questions to measure approval. Structuring questions to avoid bias. The measurement scale associated with the questions. The fact these polls tend to develop time-series data. 1.60 Nominal data or ordinal data. 1.61 Interval or ratio data. 1.62 Ratings are typical uses of ordinal scale data. And since ratings are based on personal opinion, even though people are using the same scale, a direct comparison between the two ratings is not possible. This is a common problem when people are asked to rate an object using an ordinal scale. 1.63 Answers will vary with the student. But a good discussion should include the following factors: Sampling techniques and possible problems selecting a representative sample. Determining how to measure confidence. Structuring questions to avoid bias. The measurement scale associated with the questions. The fact this poll is specifically intended to develop time-series data. 1.64 Answers will vary with the student. 1.65 Answers will vary with the student. 1.66 No because a random sample means that every item in the population has an equal chance of being selected. Individuals who do not have or use email do not have an equal chance of being included in this survey. Also, volunteer emails would not be random. In this survey the biggest drawback is that only individuals with strong feelings one way or the other are apt to respond to this survey. This could lead to a great deal of bias in the results of the survey. Another big problem with a survey is nonresponse bais. Again because they are requesting viewers to write in there will be a great deal of nonresponse to this survey. 1.67 They would probably want to sample the salsa jars as they come off the assembly line at the plant for a specified time period. They would want to use a random sample. One method would be to take a systematic random sample. They could then calculate the percentage of the sample that had an unacceptable thickness. The product is going to be ruined after testing it. You would not want to ruin the entire product that comes off the assembly line. 1.68 Student answers will vary but one method would be personal observation at grocery stores or another method would be to simply look at their sales. Are buyers of the energy drinks purchasing bottles or cans? If using personal observation just have people at grocery stores observe people over a specified period of time and note which are selecting cans and which are selecting bottles and look at the percentages of each. You would be looking at ratio data because you could have a true 0 if, for example, no one purchased bottles. Depends on the way the data are collected. Sales data would be quantitative.