These questions pertain to how to collect a random sample of 800 airline passengers from 100 particular flights leaving San Francisco International Airport. Assume there are 200 passengers aboard each flight. Describe how to draw the sample as a stratified random sample, using the 100 flights as the strata.
Q. 2One problem with using random digit dialing to get a representative sample of households in a city is that
a. the method can only be used to get a sample for the whole country.
b. households with multiple telephones on the same line will be over-represented.
c. households with multiple phone numbers will be over-represented.
d. households with unlisted phone numbers will not be represented.
Q. 3Which of the following is the best example of a population from which a cluster sample would be easier to obtain that a simple random sample?
a. Passengers who will be flying in the upcoming week on a certain airline.
b. Registered drivers in a certain state.
c. Employees of a large company.
d. Members of a national organization.
Q. 4There are five cities in a politician's district but redistricting has been proposed for the state. The politician would like to know which city he should try to remove from his district. He plans to conduct a survey to find out his approval rating. Which one of the following sampling plans would be most useful for his purposes?
a. Take a stratified sample with political parties as the strata.
b. Take a stratified sample with the five cities as the strata.
c. Take a simple random sample across his district.
d. Take a cluster sample with the five cities as clusters.
Q. 5A company that produces electronics (stereos, TV's, DVD players, etc.) is thinking about adding an incentive program to the contracts of its employees. To learn about the opinion of its employees regarding this idea, a survey will be sent out to a sample of the employees. To ensure that employees of all three plants are repre-sented in the survey, the statistician decides to take a sample of employees from each of the three plants. At each plant, a list is available of all employees. A 1-in-20 systematic sample will be taken from each plant. What sampling technique is being used to sample the employees?
a. simple random
b. cluster
c. stratified
d. multi-stage
Q. 6A librarian wants to gather data on the number of times books of fiction are checked out during the year. The library has 2000 books of fiction, of which 500 are murder mysteries, 400 are science fiction, and the rest are other. She decides to sample 120 books. Suppose the librarian decides to take a simple random sample of 30 books from the murder mystery category, 24 from the science fiction category, and the remaining 66 from the other category. What sampling technique was used?
a. simple random
b. cluster
c. stratified
d. multi-stage
Q. 7Children at a Kindergarten school are divided into three groups: Those who are the oldest/first child (there are 200 of them, call this Group I), those who are the second child (there are 150, call this Group II), and those who are the third (or even fourth or fifth) child (there are 75, call this Group III). The social worker at the school will take a sample to find out how many sleepovers they have had (without parents) at a friend's house. She suspects that first-borns do not get as many as later children, so she decides to take a simple random sample of 15 children from each of the three groups. What sampling technique will be used to obtain the sample of children?
a. stratified
b. cluster
c. simple random
d. multi-stage
Q. 8Taxpayers in a population are listed in order of increasing income, with people with the lowest incomes listed first. A sample is selected by randomly choosing one of the first 100 names, then choosing every 100th name from that point forward. This is an example of a __________ sample.
a. stratified
b. cluster
c. simple random
d. systematic
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