/*! 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 61. Critical values What critical va... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 8: Q 61. (page 541)

Critical values What critical value t*from Table B should be used for a

confidence interval for the population mean in each of the following situations?

a. A 95% confidence interval based on n=10 randomly selected observations

b. A99% confidence interval from an SRS of 20 observations

c. A 90% confidence interval based on a random sample of 77 individuals

Short Answer

Expert verified

a. The critical value is 2.262

b. The critical value is 2.861

c. The critical value is1.671

Step by step solution

01

Part (a) Step 1: Given Information

It is given that Confidence Level =95%

n=10

02

Part (a) Step 2: Calculation

Level of significance, (伪)=1-0.95=0.05

Degree of df=n-1

=10-1=9

At 5%, level of significance

t伪/2,df=z0.05/2,9=2.262

The critical value is2.262

03

Part (b) Step 1: Given Information

It is given that Confidence Level =99%

n=20

04

Part (b) Step 2: Calculation

Level of Significance, (伪)=1-0.99=0.01

Degree of freedom, df=n-1

=20-1=19

At 1%level of significance,

t伪/2,df=t0.01/2,19=2.861

The critical value is2.861

05

Part (c) Step 5: Given Infromation

It is given that Confidence Level =90%

n=77

06

Part (c) Step 2: Calculation

Level of significance, (伪)=1-0.90=0.10

Degree of freedom, df=n-1

=77-1=76

At 10%level of significance, critical value is

t伪/2,df=t0.10/2,76=1.671

The critical value is1.671

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

Suppose we want a 90% confidence interval for the average amount spent on books by freshmen in their first year at a major university. The interval is to have a margin of error of \(2. Based on last year鈥檚 book sales, we estimate that the standard deviation of the amount spent will be close to \)30. The number of observations required is closest to

(a) 25. (b) 30. (c) 608. (d) 609. (e) 865.

Check them all Determine if the conditions are met for constructing a confidence interval for the population mean in each of the following settings.

a. We want to estimate the average age at which U.S. presidents have died. So we obtain a list of all U.S. presidents who have died and their ages at death.

b. Do teens text more than they call? To find out, an AP Statistics class at a large high school collected data on the number of text messages and calls sent or received by each of 25randomly selected students. The boxplot displays the difference (Texts 鈭� Calls) for each student.

Gambling and the NCAA Gambling is an issue of great concern to those involved in college athletics. Because of this concern, the National Collegiate Athletic Association (NCAA) surveyed randomly selected student athletes concerning their gambling-related behaviors. Of the 5594Division Imale athletes who responded to the survey, 3547reported participation in some gambling behavior. This includes playing cards, betting on games of skill, buying lottery tickets, betting on sports, and similar activities. A report of this study cited a 1%margin of error.

a. The confidence level was not stated in the report. Use what you have learned to

estimate the confidence level, assuming that the NCAA took an SRS.

b. The study was designed to protect the anonymity of the student athletes who responded. As a result, it was not possible to calculate the number of students who were asked to respond but did not. How does this fact affect the way that you interpret the results?

It鈥檚 critical Find the appropriate critical value for constructing a confidence interval in each of the following settings.

a. Estimating a population proportion p at a 94% confidence level based on an SRS of size 125

b. Estimating a population mean 渭 at a 99% confidence level based on an SRS of size 58

In preparing to construct a one-sample t interval for a population mean, suppose we are not sure if the population distribution is Normal. In which of the following circumstances would we not be safe constructing the interval based on an SRS of size14from the population?

a. A stemplot of the data is roughly bell-shaped.

b. A histogram of the data shows slight skewness.

c. A boxplot shows that the values above the median are much more variable than the values below the median.

d. The sample standard deviation is large.

e. The sample standard deviation is small.
See all solutions

Recommended explanations on Math Textbooks

Probability and Statistics

Read Explanation

Theoretical and Mathematical Physics

Read Explanation

Geometry

Read Explanation

Applied Mathematics

Read Explanation

Decision Maths

Read Explanation

Statistics

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.