/*! 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.110 Forbes magazine published data o... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Forbes magazine published data on the best small firms in 2012. These were firms that had been publicly traded for at least a year, have a stock price of at least \(5per share, and have reported annual revenue between \)5million and$1 billion.

The Table 8.13 shows the ages of the corporate CEOs for a random sample of these firms.

Use this sample data to construct a 90%confidence interval for the mean age of CEO’s for these top small firms. Use the Student's t-distribution.

Short Answer

Expert verified

We estimate that the average age of all CEOs of the greatest small businesses is between $54.421and$58.713 years, with a95% confidence level.

Step by step solution

01

Introduction

Create a 90%confidence interval for the average age of CEOs for these top small businesses using this sample data. The Student's-t distribution should be used.

02

Explanation 

Calculate the point estimate first.

x¯=56.567

Calculate the samples' standard deviations.

s=6.907,n=30,anddf=30-1=29

CL=0.90

α=1-CL

=1-0.90=0.10a2=0.05ta2=t0.05=1.699

EBM=ta2sn

EBM=1.699690730

EBM=2.143

x¯-EBM=56.567-2.146

x¯-EBM=54.421

x¯+EBM=56.567+2.146

x¯+EBM=58.713

03

Result

We estimate that the average age of all CEOs of the greatest small businesses is between $54.421and$58.713 years, with a 95% confidence level.

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

Suppose the Census needed to be 98% confident of the population mean length of time. Would the Census have to survey more people? Why or why not?

Announcements for 84 upcoming engineering conferences were randomly picked from a stack of IEEE Spectrum

magazines. The mean length of the conferences was 3.94 days, with a standard deviation of 1.28 days. Assume the

underlying population is normal.

a. In words, define the random variables X and X

b. Which distribution should you use for this problem? Explain your choice.

c. Construct a 95% confidence interval for the population mean length of engineering conferences.

I. State the confidence interval.

ii. Sketch the graph.

iii. Calculate the error bound.

Using the same p′ and level of confidence, suppose that n were increased to 100. Would the error bound become larger

or smaller? How do you know?

In words, define the random variable X¯ .

The Federal Election Commission (FEC) collects information about campaign contributions and disbursements for

candidates and political committees each election cycle. A political action committee (PAC) is a committee formed to raise

money for candidates and campaigns. A Leadership PAC is a PAC formed by a federal politician (senator or representative)

to raise money to help other candidates’ campaigns.

The FEC has reported financial information for 556Leadership PACs that operating during the 2011–2012election cycle.

The following table shows the total receipts during this cycle for a random selection of 30Leadership PACs.

̄x=\(251,854.23

s=\)521,130.41

Use this sample data to construct a 96%confidence interval for the mean amount of money raised by all Leadership PACs

during the 2011–2012election cycle. Use the Student's t-distribution.

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.