/*! 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} Q 42. September 11 A recent study aske... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

September 11 A recent study asked U.S. adults to name 10historic events that occurred in their lifetime that have had the greatest impact on the country. The most frequently chosen answer was the September 11,2001, terrorist attacks, which was included by 76%of the 2025randomly selected U.S. adults. Construct and interpret a 95%confidence interval for the proportion of all U.S. adults who would include the 9/11attacks on their list of 10historic events.

Short Answer

Expert verified

For population proportion,95%confidence interval is0.7414<p<0.7786

Step by step solution

01

Given Information

It is given that n=2025

p^=76%=0.76

Confidence Level=0.95

02

Concept Used

Formula to be used:

p^=xn(Sample Proportion)

E=Zα/2×p^(1-p^)n(Margin of Error)

(p^-E,p^+E)(Confidence Interval)

03

Conditions

  • Random Selection: This is satisfied as US adults are selected randomly.
  • Less than 10% population: Adults are less than 10%of US adults. This condition is satisfied.
  • np^andn(1-p^)must be≥10: Here np^=2025×0.76=1539≥10andn(1-p^)=2025×(1-0.76)=486≥10which is met. This condition is also satisfied.

All conditions are met.

04

Calculation

Confidence level is 0.95

Level of significance is a=0.05

Zc=Za/2critical value=1.96

Margin of error is

E=1.96×0.76(1-0.76)2025

Confidence interval is (0.76-0.0186,0.76+0.0186)

data-custom-editor="chemistry" (0.7414,0.7786)

E=0.0186

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 91Ó°ÊÓ!

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

The student body president of a high school claims to know the names of at least 1000of the 1800 students who attend the school. To test this claim, the student government advisor randomly selects 100students and asks the president to identify each by name. The president successfully names only 46of the students.

a. Identify the population and parameter of interest.

b. Check conditions for constructing a confidence interval for the parameter.

c. Construct a 99%confidence interval for p.

d. Interpret the interval in context.

Bone loss by nursing mothers Breast-feeding mothers secrete calcium into

their milk. Some of the calcium may come from their bones, so mothers may lose bone mineral. Researchers measured the percent change in bone mineral content (BMC) of the spines of 47randomly selected mothers during three months of breast-feeding. The mean change in BMC was −3.587%and the standard deviation was 2.506%

a. Construct and interpret a 99%confidence interval to estimate the mean percent change in BMC in the population of breast-feeding mothers.

b. Based on your interval from part (a), do these data give convincing evidence that

nursing mothers lose bone mineral, on average? Explain your answer.

Election polling Gloria Chavez and Ronald Flynn are the candidates for mayor in a large city. We want to estimate the proportion p of all registered voters in the city who plan to vote for Chavez with 95%confidence and a margin of error no greater than 0.03. How large a random sample do we need?

How many pairs of shoes, on average, do female teens have? To find out, an AP Statistics class selected an SRS of 20female students from their school. Then they recorded the number of pairs of shoes that each student reported having. Here are the data:

Check whether each of the conditions is met for calculating a confidence interval for the population proportion

Salty chips A quality control inspector takes a random sample of 25 bags of potato chips from the thousands of bags filled in an hour. Of the bags selected, 3 had too much salt.

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.