/*! 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 39. Home computers聽Refer to Exercis... [FREE SOLUTION] | 91影视

91影视

Home computersRefer to Exercise 35.

a. Explain why the sample result gives some evidence for the alternative hypothesis.

b. Calculate the standardized test statistic and P-value.

c. What conclusion would you make?

Short Answer

Expert verified

a. Sample proportion of 0.6833<0.80.

b. Z=-2.26and P=0.0119

c. There is convincing proof that proportion of all students at researcher's high school who owns computer is less than0.80

Step by step solution

01

Part (a) Step 1: Given Information

It is given that =0.05

H0:p=0.80

H1:p<0.80

n=60,x=41

02

Part (a) Step 2: Calculation

We know that p^=xn

Hence, sample proportion is p^=xn=4160=0.6833

0.6833<0.80, the sample results give some evidence for alternate hypothesis as it agrees to alternate hypothesisH1:p<0.80

03

Part (b) Step 1: Given Information

It is given that =0.05

H0:p=0.80

H1:p<0.80

n=60,x=41

04

Part (b) Step 2: Explanation

The sample proportion is p^=xn=4160=0.6833

Test statistics z=p^-p0p01-p0n=0.6833-0.800.80(1-0.80)60=-2.26

The Pvalue is probability of obtaining value of test static, or more extreme value, if null hypothesis is true.

Hence, Pvalue is

P=P(z<-2.26)=0.0119

05

Part (c) Step 1: Given Information

It is given that =0.05

H0:p=0.80

H1:p<0.80

n=60,x=41

06

Part (c) Step 2: Explanation

Sample proportion is p^=xn=4160=0.6833

Test statistic is

z=p^-p0p01-p0n=0.6833-0.800.80(1-0.80)60=-2.26

Pvalue using normal probability table is:

P=P(z<-2.26)=0.0119

P<0.05RejectH0

Enough convincing proof is that proportion of all students at researcher's high school who owns computer is less than0.80

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

Watching grass grow The germination rate of seeds is defined as the proportion of seeds that sprout and grow when properly planted and watered. A certain variety of grass seed usually has a germination rate of 0.80. A company wants to see if spraying the seeds with a chemical that is known to increase germination rates in other species will increase the germination rate of this variety of grass. The company researchers spray a random sample of 400grass seeds with the chemical, and 339of the seeds germinate. Do these data provide convincing evidence at the =0.05 significance level that the chemical is

effective for this variety of grass?

1 A software company is trying to decide whether to produce an upgrade of one of its programs. Customers would have to pay \(100 for the upgrade. For the upgrade to be profitable, the company must sell it to more than 20% of their customers. You contact a random sample of 60 customers and find that 16 would be willing to pay \)100 for the upgrade.

a. Do the sample data give convincing evidence that more than 20% of the company鈥檚 customers are willing to purchase the upgrade? Carry out an appropriate test at the =0.05significance level.

b. Which would be a more serious mistake in this setting鈥攁 Type I error or a Type II error? Justify your answer.

c. Suppose that 30% of the company鈥檚 customers would be willing to pay $100 for the upgrade. The power of the test to detect this fact is0.60. Interpret this value.

Jump around Student researchers Haley, Jeff, and Nathan saw an article on the Internet claiming that the average vertical jump for teens was 15 inches. They wondered if the average vertical jump of students at their school differed from 15 inches, so they obtained a list of student names and selected a random sample of 20 students. After contacting these students several times, they finally convinced them to allow their vertical jumps to be measured. Here are the data (in inches):

Do these data provide convincing evidence at the =0.10 level that the average vertical jump of students at this school differs from 15 inches?

Fair coin? You want to determine if a coin is fair. So you toss it 10times and record the proportion of tosses that land 鈥渉eads.鈥 You would like to perform a test of H0:p=0.5versus Ha:p0.5, where p= the proportion of all tosses of the

coin that would land 鈥渉eads.鈥 Check if the conditions for performing the significance test are met.

Making conclusions A student performs a test of H0:=12versus Ha:12

at the =0.05significance level and gets a P-value of 0.01. The

student writes: 鈥淏ecause the P-value is small, we reject H0. The data prove that Hais true.鈥 Explain what is wrong with this conclusion.

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.