Login Registrieren

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

The Practice of Statistics for AP Examination

Daren Starnes, Josh Tabor

$Math Studyset Vaia Explanations$ Math

6th Edition · 837 pages

ISBN: 9781319113339

Chapter 9: Q 100. (page 610)

Ages of presidents Joe is writing a report on the backgrounds of American presidents. He looks up the ages of all the presidents when they entered office. Because Joe took a statistics course, he uses these numbers to perform a significance test about the mean age of all U.S. presidents. Explain why this makes no sense.

Short Answer

Expert verified

This mean age is required to perform a significance test.

Step by step solution

01

Given information

Joe is researching the backgrounds of American presidents for a report, and he checks up the ages of all presidents at the time they took office.

02

Calculation

There is no average age at which presidents should be expected to be the same. To do a significance test, you'll need this average age.

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

Don't argue Refer to Exercise 2. Yvonne finds that $96$ of the $150$ students $(64 %)$ say they rarely or never argue with friends. A significance test yields a $P$ -value of $0.0291$ Interpret the $P$ -value.

We want to be rich In a recent year, $73 %$ of first-year college students responding to a national survey identified “being very well-off financially” as an important personal goal. A state university finds that $132$ of an SRS of $200$ of its first-year students say that this goal is important. Is there convincing evidence at the $α = 0.05$ significance level that the proportion of all first-year students at this university who think being very well-off is important differs from the national value of 73%?

Interpreting a P-value A student performs a test of $H 0 : p = 0.3 H_{0} : p = 0.3$ versus Ha: $p < 0.3 H_{a} : p < 0.3$ and gets a $P$ -value of $0.22$ The student says, "This means there is about a $22 %$ chance that the null hypothesis is true." Explain why the student's explanation is wrong.

A significance test allows you to reject a null hypothesis $H 0 H_{0}$ in favor of an alternative hypothesis ${Ha}_{a}$ at the $5 %$ significance level. What can you say about significance at the $1 %$ level?

a. $H 0 H_{0}$ can be rejected at the $1 %$ significance level.

b. There is insufficient evidence to reject $H_{0} H_{0}$ at the $1 %$ significance level.

c. There is sufficient evidence to accept $H_{0} H_{0}$ at the $1 %$ significance level.

d. ${Ha}^{H_{a}}$ can be rejected at the $1 %$ significance level.

e. The answer can't be determined from the information given.

Paying high prices? A retailer entered into an exclusive agreement with a supplier who guaranteed to provide all products at competitive prices. To be sure the supplier honored the terms of the agreement, the retailer had an audit performed on a random sample of 25 invoices. The percent of purchases on each invoice for which an alternative supplier offered a lower price than the original supplier was recorded.17 For example, a data value

of 38 means that the price would be lower with a different supplier for 38% of the items on the invoice. A histogram and some numerical summaries of the data are shown here. The retailer would like to determine if there is convincing evidence that the mean percent of purchases for which an alternative supplier offered lower prices is greater than 50% in the population of this company’s invoices.

a. State appropriate hypotheses for the retailer’s test. Be sure to define your parameter.

b. Check if the conditions for performing the test in part (a) are met.

See all solutions

Recommended explanations on Math Textbooks

Decision Maths

Read Explanation

Calculus

Read Explanation

Statistics

Read Explanation

Probability and Statistics

Read Explanation

Applied Mathematics

Read Explanation

Theoretical and Mathematical Physics

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