Statistics and Probability

Approval rating A newspaper article reported that a poll based on a sample of 1150 residents of a ...

Approval rating A newspaper article reported that a poll based on a sample of 1150 residents of a ...

[html]Approval rating A newspaper article reported that a poll based on a sample of 1150 residents of a state showed that the state's Governor's job approval rating stood at 58%. They claimed a margin of error

be beautiful   83   1 Reply

purplepanda1516

Pumpkin pie A can of pumpkin pie mix contains a mean of 30 ounces and a standard deviation of 2 ...

Pumpkin pie A can of pumpkin pie mix contains a mean of 30 ounces and a standard deviation of 2 ...

[html]Pumpkin pie A can of pumpkin pie mix contains a mean of 30 ounces and a standard deviation of 2 ounces. The contents of the cans are normally distributed. What is the probability that four randomly select

tlc_71111   87   2 Replies

tlc_71111

Depression A recent psychiatric study from the University of Southampton observed a higher incidence ...

Depression A recent psychiatric study from the University of Southampton observed a higher incidence ...

[html]Depression A recent psychiatric study from the University of Southampton observed a higher incidence of depression among women whose birth weight was less than 6.6 pounds than in women whose birth weight

justinw2200   82   1 Reply

krobdance

Truckers On many highways state police officers conduct inspections of driving logbooks from large ...

Truckers On many highways state police officers conduct inspections of driving logbooks from large ...

[html]Truckers On many highways state police officers conduct inspections of driving logbooks from large trucks to see if the trucker has driven too many hours in a day. At one truck inspection station they iss

lizsmith   75   3 Replies

rinderbik

Tax advice Each year people who have income file income tax reports with the government. In some ...

Tax advice Each year people who have income file income tax reports with the government. In some ...

[html]Tax advice Each year people who have income file income tax reports with the government. In some instances people seek advice from accountants and financial advisors regarding their income tax situations.

barmour44   92   1 Reply

MikaelDevost

A certain population is strongly skewed to the left. We want to estimate its mean, so we collect a ...

A certain population is strongly skewed to the left. We want to estimate its mean, so we collect a ...

[html]A certain population is strongly skewed to the left. We want to estimate its mean, so we collect a sample. Which should be true if we use a large sample rather than a small one?
I.   The distribution of our sample data will be more clearly

Gideon123   71   2 Replies

Gideon123

Which is true about a 99% confidence interval based on a given sample?I. The interval contains 99% ...

Which is true about a 99% confidence interval based on a given sample?I. The interval contains 99% ...

[html]Which is true about a 99% confidence interval based on a given sample?
I.   The interval contains 99% of the population.
II.  Results from 99% of all samples will lie in this interval.
III. The interval is wider than a 95% confid

toripollard8   77   1 Reply

jzhu11

We have calculated a confidence interval based on a sample of n = 180. Now we want to get a better ...

We have calculated a confidence interval based on a sample of n = 180. Now we want to get a better ...

[html]We have calculated a confidence interval based on a sample of n = 180. Now we want to get a better estimate with a margin of error only one third as large. We need a new sample with

BenAff   71   3 Replies

Jax

An online catalog company wants on-time delivery for at least 90% of the orders they ship. They have ...

An online catalog company wants on-time delivery for at least 90% of the orders they ship. They have ...

[html]An online catalog company wants on-time delivery for at least 90% of the orders they ship. They have been shipping orders via UPS and FedEx but will switch to a more expensive service (ShipFast) if there is evidence that this service can exceed

parneetgill   98   1 Reply

Btllllll

A researcher investigating whether joggers are less likely to get colds than people who do not jog ...

A researcher investigating whether joggers are less likely to get colds than people who do not jog ...

[html]A researcher investigating whether joggers are less likely to get colds than people who do not jog found a P-value of 3%. This means that:

▸ There's a 3% chance that joggers get fewer colds.

▸ Joggers

be beautiful   73   2 Replies

be beautiful

To plan the budget for next year a college needs to estimate what impact the current economic ...

To plan the budget for next year a college needs to estimate what impact the current economic ...

[html]To plan the budget for next year a college needs to estimate what impact the current economic downturn might have on student requests for financial aid. Historically, this college has provided aid to 35% of its students. Officials look at a ran

rsbains   85   1 Reply

Curtis x9

We are about to test a hypothesis using data from a well-designed study. Which is true?I. A large ...

We are about to test a hypothesis using data from a well-designed study. Which is true?I. A large ...

[html]We are about to test a hypothesis using data from a well-designed study. Which is true?
I.   A large P-value would be strong evidence against the null hypothesis.
II.  We can set a higher standard of proof by choosing α = 10% instead

sjbux   105   2 Replies

sjbux

Suppose that a device advertised to increase a car's gas mileage really does not work. We test it ...

Suppose that a device advertised to increase a car's gas mileage really does not work. We test it ...

[html]Suppose that a device advertised to increase a car's gas mileage really does not work. We test it on a small fleet of cars (with H0: not effective), and our data results in a P-value of 0.004.

barry1999   57   1 Reply

Antoinette12

We will test the hypothesis that p = 60% versus p > 60%. We don't know it, but actually p is 70%. ...

We will test the hypothesis that p = 60% versus p > 60%. We don't know it, but actually p is 70%. ...

[html]We will test the hypothesis that p = 60% versus p > 60%. We don't know it, but actually p is 70%. With which sample size

Begonia   66   2 Replies

Begonia

A college alumni fund appeals for donations by phoning or emailing recent graduates. A random sample ...

A college alumni fund appeals for donations by phoning or emailing recent graduates. A random sample ...

[html]A college alumni fund appeals for donations by phoning or emailing recent graduates. A random sample of 300 alumni shows that 40% of the 150 who were contacted by telephone actually made contributions compared to only 30% of the 150 who receive

emlaai   77   1 Reply

mace

Births A city has two hospitals, with many more births recorded at the larger hospital than at the ...

Births A city has two hospitals, with many more births recorded at the larger hospital than at the ...

[html]Births A city has two hospitals, with many more births recorded at the larger hospital than at the smaller one. Records indicate that in general babies are about equally likely to be boys or girls, but th

meganA   271   2 Replies

meganA

Which of the following will make a confidence interval narrower?I. increase the confidence level.II. ...

Which of the following will make a confidence interval narrower?I. increase the confidence level.II. ...

Which of the following will make a confidence interval narrower?
I. increase the confidence level.
II. take a larger sample.
III. take a smaller sample.

▸ I only

▸ I and III

▸ I and II

▸ III only

▸ II only

joanne1718   76   1 Reply

Btllllll

When you construct a 90% confidence interval for a population proportion based on a sample, what is ...

When you construct a 90% confidence interval for a population proportion based on a sample, what is ...

[html]When you construct a 90% confidence interval for a population proportion based on a sample, what is it that you are pretty sure is in your interval?
I. 90% of the sample data.
II. 90% of all sample proportions.
III. The populatio

Kaevyn04   108   2 Replies

Kaevyn04

We have calculated a confidence interval based on a sample of size n = 100. After looking over our ...

We have calculated a confidence interval based on a sample of size n = 100. After looking over our ...

[html]We have calculated a confidence interval based on a sample of size n = 100. After looking over our work, we realized that the sample size was actually 400. How will the corrected interval compare to the

victor.m.rojas2   82   1 Reply

Gparker

Which is true about the sampling distribution of a statistic with sample size n?I. The sampling ...

Which is true about the sampling distribution of a statistic with sample size n?I. The sampling ...

[html]Which is true about the sampling distribution of a statistic with sample size n?
I. The sampling distribution of the statistic will be approximately normal.
II. The spread of the sampling distr

seeb1999   88   2 Replies

seeb1999

A city planner wants to construct a confidence interval for the proportion of workers who would take ...

A city planner wants to construct a confidence interval for the proportion of workers who would take ...

[html]A city planner wants to construct a confidence interval for the proportion of workers who would take public transportation to work if it were available. What sample size should he use to estimate the proportion to within 4 percentage points at

Frost   79   1 Reply

jeromet1

Which of the following would increase the power of a test?I. Increase the sample size II. Decrease ...

Which of the following would increase the power of a test?I. Increase the sample size II. Decrease ...

Which of the following would increase the power of a test?
I. Increase the sample size
II. Decrease the significance level
III. Increase alpha

▸ II only

▸ I only

▸ I and III

▸ I and II

▸ III only

parneetgill   89   2 Replies

parneetgill

A statistician consulting for a state department of transportation conducts a study to see if the ...

A statistician consulting for a state department of transportation conducts a study to see if the ...

[html]A statistician consulting for a state department of transportation conducts a study to see if the proportion of drivers who are intoxicated has decreased since last year.
H0: The proportion is the same as last year
Ha

D-john   73   1 Reply

Cass Stein

A pharmaceutical company has a drug they think is better at lowering blood pressure than the current ...

A pharmaceutical company has a drug they think is better at lowering blood pressure than the current ...

[html]A pharmaceutical company has a drug they think is better at lowering blood pressure than the current medication, but it costs more money for consumers. They conduct a significance test on their clinical study (H0: The new drug works

Tneary   86   2 Replies

Tneary

Pew research reported in 2013 that 15% of American adults do not use the internet or e-mail. They ...

Pew research reported in 2013 that 15% of American adults do not use the internet or e-mail. They ...

[html]Pew research reported in 2013 that 15% of American adults do not use the internet or e-mail. They report a margin of error of 2.3 percentage points. The meaning of that margin of error is:

▸ They are pretty sure that the poll result differs fr

stevengu246   75   1 Reply

abonaccorso1

We conduct a significance test with H0: p = 0.43 and Ha: p 0.43. We take a sample of size 250 and ...

We conduct a significance test with H0: p = 0.43 and Ha: p 0.43. We take a sample of size 250 and ...

[html]We conduct a significance test with H0: p = 0.43 and Ha: p ≠ 0.43. We take a sample of size 250 and get a sample proportion of 0.40. The app

DragoxCM16   59   2 Replies

DragoxCM16

Gun ownership Concerned about recent incidence of gun violence, a public interest group conducts a ...

Gun ownership Concerned about recent incidence of gun violence, a public interest group conducts a ...

[html]Gun ownership Concerned about recent incidence of gun violence, a public interest group conducts a poll of 850 randomly selected American adults and finds that 44% of those surveyed have a gun in their ho

be beautiful   73   1 Reply

kwashington67

Heights American females aged 20 to 29 years old have heights that are approximately normally ...

Heights American females aged 20 to 29 years old have heights that are approximately normally ...

[html]Heights American females aged 20 to 29 years old have heights that are approximately normally distributed with a mean of 64.5 inches and a standard deviation of 2.5 inches.
a. If you randomly select

toripollard8   99   2 Replies

toripollard8

Hamsters You have ten hamsters. Their weights in grams are 134, 142, 148, 151, 152, 155, 158, 160, ...

Hamsters You have ten hamsters. Their weights in grams are 134, 142, 148, 151, 152, 155, 158, 160, ...

[html]Hamsters You have ten hamsters. Their weights in grams are 134, 142, 148, 151, 152, 155, 158, 160, 164, 167. Describe a procedure to create a simulated sampling distribution of the sample maximum weight f

Lopezj273   124   1 Reply

jfinn1021

Internet Question 9 described a Pew Research poll that found 15% of American adults do not use the ...

Internet Question 9 described a Pew Research poll that found 15% of American adults do not use the ...

Internet Question 9 described a Pew Research poll that found 15% of American adults do not use the internet or e-mail with a margin of error of 2.3% and 95% confidence. What was the sample size?

JisselFlores   99   2 Replies

JisselFlores

Health care Organizations like Gallup often track public opinion on many issues by asking the same ...

Health care Organizations like Gallup often track public opinion on many issues by asking the same ...

[html]Health care Organizations like Gallup often track public opinion on many issues by asking the same question at different times. In October of 2013, Gallup reported that 52% of U.S. adults disapprove of th

Yessi15   69   1 Reply

qwer34

A professor at a large university believes that students take an average of 15 credit hours per ...

A professor at a large university believes that students take an average of 15 credit hours per ...

[html]A professor at a large university believes that students take an average of 15 credit hours per term. A random sample of 24 students in her class of 250 students reported the following number of credit hours tha

barmour44   94   4 Replies

cooldawg69

Insurance companies track life expectancy information to assist in determining the cost of life ...

Insurance companies track life expectancy information to assist in determining the cost of life ...

[html]Insurance companies track life expectancy information to assist in determining the cost of life insurance policies. The insurance company knows that, last year, the life expectancy of its policyholders was 77 ye

yufeige4   75   2 Replies

yufeige4

Insurance companies track life expectancy information to assist in determining the cost of life ...

Insurance companies track life expectancy information to assist in determining the cost of life ...

[html]Insurance companies track life expectancy information to assist in determining the cost of life insurance policies. The insurance company knows that, last year, the life expectancy of its policyholders was 77 ye

Biraj   68   1 Reply

h00304413

Textbook authors must be careful that the reading level of their book is appropriate for the target ...

Textbook authors must be careful that the reading level of their book is appropriate for the target ...

[html]Textbook authors must be careful that the reading level of their book is appropriate for the target audience. Some methods of assessing reading level require estimating the average word length. We've randomly ch

lstar1993   82   2 Replies

lstar1993

Textbook authors must be careful that the reading level of their book is appropriate for the target ...

Textbook authors must be careful that the reading level of their book is appropriate for the target ...

[html]Textbook authors must be careful that the reading level of their book is appropriate for the target audience. Some methods of assessing reading level require estimating the average word length. We've randomly ch

unicorngirl13   81   1 Reply

Nikki_LYNN

The average American sees 3.9 movies at the theater each year. A curious student polls 30 friends ...

The average American sees 3.9 movies at the theater each year. A curious student polls 30 friends ...

[html]The average American sees 3.9 movies at the theater each year. A curious student polls 30 friends and family over the course of a week. He finds that his friends have seen an average of 4.5 movies with a standar

zar   108   8 Replies

nick1116

A random sample of 13 men and 19 women in a college class reported their grade point averages ...

A random sample of 13 men and 19 women in a college class reported their grade point averages ...

[html]A random sample of 13 men and 19 women in a college class reported their grade point averages (GPAs). Here are histograms from the data:

Villerys39   138   4 Replies

Hpreet796

Every year favorite songs compete to be on a Top 200 list based upon sales and rankings by the ...

Every year favorite songs compete to be on a Top 200 list based upon sales and rankings by the ...

[html]Every year favorite songs compete to be on a Top 200 list based upon sales and rankings by the experts in the music industry. These songs have many characteristics, such as song length and beats per minute, whic

regina nana   149   4 Replies

Crystalboo92

A total of 23 Gossett High School students were admitted to State University. Of those students, 7 ...

A total of 23 Gossett High School students were admitted to State University. Of those students, 7 ...

[html]A total of 23 Gossett High School students were admitted to State University. Of those students, 7 were offered athletic scholarships. The school's guidance counselor looked at their composite ACT scores (shown

DragoxCM16   153   4 Replies

coolcat