Logout Open In App
Open In App
Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Chapter 8: Q 71. (page 542)

America’s favorite cookie Ann and Tori wanted to estimate the average weight of an Oreo cookie to determine if it was less than advertised (34 grams for 3 cookies). They selected a random sample of 36cookies and found the weight of each cookie (in grams). The mean weight was x̄=11.3921grams with a standard deviation of sX=0.0817grams. Construct and interpret a 90%confidence interval for the true mean weight of an Oreo cookie.

Short Answer

Expert verified

The confidence interval is(11.37,11.42).

Step by step solution

01

Given Information

It is given that (x¯)=11.3921

sx=0.0817

n=36

02

Concept Used

tconfidence interval for population mean is calculated as:

CI=x¯±tα/2,df×sn

03

Calculation

As standard deviation is not known, tconfidence interval is used.

Excel gives output as:

Confidence Interval is(11.37,11.42)

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

Rating school food Latoya wants to estimate the proportion of the seniors

at her boarding school who like the cafeteria food. She interviews an SRS of 50of the 175 seniors and finds that 14 think the cafeteria food is good.

The 10%condition When constructing a confidence interval for a population proportion, we check that the sample size is less than 10%of the population size.

a. Why is it necessary to check this condition?

b. What happens to the capture rate if this condition is violated?

Age and video games Refer to Exercise 41. The study also estimated that 67% of adults aged 18–29play video games, but only 25%of adults aged 65and older play video games.

a. Explain why you do not have enough information to give confidence intervals for these two age groups separately.

b. Do you think a 95% confidence interval for adults aged 18–29 would have a larger or smaller margin of error than the estimate from Exercise 41? Explain your answer.

A Gallup poll found that only 28%of American adults expect to inherit money or valuable possessions from a relative. The poll’s margin of error was ±3 percentage points at a 95%confidence level. This means that

a. the poll used a method that gets an answer within 3% of the truth about the population 95%of the time.

b. the percent of all adults who expect an inheritance must be between 25%and 31%.

c. if Gallup takes another poll on this issue, the results of the second poll will lie between 25%and 31%.

d. there’s a 95% chance that the percent of all adults who expect an inheritance is between

25% and 31%.

e. Gallup can be 95% confident that between 25% and 31% of the sample expect an inheritance.

More prayer in school Refer to Exercise 5. Interpret the confidence level.
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Statistics

Read Explanation

Probability and Statistics

Read Explanation

Mechanics Maths

Read Explanation

Pure Maths

Read Explanation

Geometry

Read Explanation
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.

Sign-up for free