One-sided test Suppose you carry out a significance test of H0:μ=5versus Ha:μ>5based on a sample of size n=20and obtain t=1.81.

(a) Find the P-value for this test using (i) Table Band (ii) your calculator. What conclusion would you draw at the 5%significance level? At the 1%significance level?

(b) Redo part (a) using an alternative hypothesis ofHa:μ5.

Short Answer

Expert verified

a. Table B: 0.025<P-value<0.05. Technology: the P-value is 0.043. Reject H0 at the 5%significance level. Fail to reject H0at the 1%significance level.

b. Table B: 0.05<P-value<0.10. Technology: the P-value is 0.086. Fail to reject H0at both levels.

Step by step solution

01

Given information

(One-sided test Suppose you carry out a significance test of H0:μ=5versus Ha:μ>5based on a sample of size n=20and obtain t=1.8.

02

Explanation (part a)

(i) Table B:

The degrees of freedom required for looking Table B: is given by df=n-1=20-1=19

Now for a one tailed significance t test looking at Table B: the p-value is calculated as

localid="1651324003883" 0.025<P-value<0.05

(ii) Calculator:

Performing test on significance level 0.05: p-value:0.04388018

Decision: You can rejectHat the significance level 0.05, because your p-value does not exceed 0.05.

Performing test on significance level 0.1:p-value:0.9561198

Decision: There is not enough evidence to rejectH at the significance level 0.1, because your p-value is greater than 0.1.

Conclusion: Reject H0 at the 5%significance level. Fail to reject H0at the 1%significance level.

03

Explanation (part b)

Redo part (a) using an alternative hypothesis of Ha:μ5

(i) Table B:

The degrees of freedom required for looking Table B: is given by

df=n-1=20-1=19

Now for a one tailed significance t test looking at Table B: the p-value is calculated as

0.05<P-value<0.1

(ii) Calculator:

Performing test on significance level 0.05: p-value:0.08776036

Decision: There is not enough evidence to rejectH at the significance level 0.05, because your p-value is greater than 0.05.

Performing test on significance level 0.1: p-value:0.08776036

Decision: You can rejectH at the significance level 0.1, because your p-value does not exceed 0.1.

Conclusion: Fail to reject H0at both levels.

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Most popular questions from this chapter

Is it significant? For students without special preparation, SAT Math scores in recent years have varied Normally with mean μ=518. One hundred students go through a rigorous training program designed to raise their SAT Math scores by improving their mathematics skills. Use your calculator to carry out a test of

H0:μ=518

Hα:μ>518

in each of the following situations.

(a) The students' scores have mean x¯=536.7and standard deviation sx=114. Is this result significant at the5%level?

(b) 'The students' scores have mean x=537.0and standard deviation sx=114. Is this result significant at the 5%level?

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Describe a Type I error in this setting.

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