/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q24 Critical Thinking. In Exercises ... [FREE SOLUTION] | 91影视

91影视

Critical Thinking. In Exercises 17鈥28, use the data and confidence level to construct a confidence interval estimate of p, then address the given question.

Nonvoters Who Say They Voted In a survey of 1002 people, 70% said that they voted in a recent presidential election (based on data from ICR Research Group). Voting records show that 61% of eligible voters actually did vote.

a. Find a 98% confidence interval estimate of the proportion of people who say that they voted.

b. Are the survey results consistent with the actual voter turnout of 61%? Why or why not?

Short Answer

Expert verified

a. The 98% confidence interval is equal to (0.666,0.734).

b. No, the survey results are not consistent with the actual voter turnout of 61%.

Step by step solution

01

Given Information

The information about the voting percentage in an election is given. In a sample of 1002 people, 70% said that they voted in the election. 61% of the eligible voters actually did vote.

02

Calculation of the sample proportion

The sample size (n) is equal to 1002.

The sample proportion of voters who said they voted in the election is given below:

p^=70%=70100=0.70

The value of the sample of proportion is equal to 0.70.

The sample proportion of voters who did not vote in the election is given below:

q^=1-p^=1-0.70=0.30

03

Calculation of the margin of error

The given level of significance is 0.02.

Therefore, the value of z2form the standard normal table is equal tois equal to 2.3263.

The margin of error is equal to

E=z2p^q^n=2.32630.700.301002=0.0337

Therefore, the margin of error is equal to 0.0337.

04

Calculation of the confidence interval

a.

The 98% confidence interval has the following value:

p^-E<p<p^+E0.70-0.0337<p<0.70+0.03370.666<p<0.734

Thus, the 98% confidence interval is equal to (0.666,0.734).

05

Conclusion

b.

The actual voter turnout is equal to 61% or 0.61.

The confidence interval does not contain the value of 0.61 and contains all values greater than 0.61.

This means that people have lied about voting in the election.

Therefore, the survey results are not consistent with the actual voter turnout of 61%.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Finding Critical Values. In Exercises 5鈥8, find the critical value that corresponds to the given confidence level.

99%

Insomnia Treatment A clinical trial was conducted to test the effectiveness of the drug zopiclone for treating insomnia in older subjects. Before treatment with zopiclone, 16 subjects had a mean wake time of 102.8 min. After treatment with zopiclone, the 16 subjects had a mean wake time of 98.9 min and a standard deviation of 42.3 min (based on data from 鈥淐ognitive Behavioral Therapy vs Zopiclone for Treatment of Chronic Primary Insomnia in Older Adults,鈥 by Sivertsen et al., Journal of the American Medical Association, Vol. 295, No. 24). Assume that the 16 sample values appear to be from a normally distributed population and construct a 98% confidence interval estimate of the mean wake time for a population with zopiclone treatments. What does the result suggest about the mean wake time of 102.8 min before the treatment? Does zopiclone appear to be effective?

Determining Sample Size. In Exercises 19鈥22, assume that each sample is a simple random sample obtained from a normally distributed population. Use Table 7-2 on page 338 to find the indicated sample size.

IQ of statistics professors You want to estimate for the population of IQ scores of statistics professors. Find the minimum sample size needed to be 95% confident that the sample standard deviation s is within 1% of . Is this sample size practical?

Sample Size. In Exercises 29鈥36, find the sample size required to estimate the population mean.

Mean IQ of College Professors the Wechsler IQ test is designed so that the mean is 100 and the standard deviation is 15 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of college professors. We want to be 99% confident that our sample mean is within 4 IQ points of the true mean. The mean for this population is clearly greater than 100. The standard deviation for this population is less than 15 because it is a group with less variation than a group randomly selected from the general population; therefore, if we use=15 we are being conservative by using a value that will make the sample size at least as large as necessary. Assume then that =15and determine the required sample size. Does the sample size appear to be practical?

Celebrity Net Worth Listed below are the amounts of net worth (in millions of dollars) of these ten wealthiest celebrities: Tom Cruise, Will Smith, Robert De Niro, Drew Carey, George Clooney, John Travolta, Samuel L. Jackson, Larry King, Demi Moore, and Bruce Willis. Construct a 98% confidence interval. What does the result tell us about the population of all celebrities? Do the data appear to be from a normally distributed population as required?

250 200 185 165 160 160 150 150 150 150

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.