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Significance tests A test of Ho:p=0.5versus Ha:p>0.5based on

a sample of size 200yields the standardized test statistic z=2.19. Assume that the conditions for performing inference are met.

a. Find and interpret the P-value.

b. What conclusion would you make at the α=0.01 significance level? Would

your conclusion change if you used α=0.05 instead? Explain your reasoning.

c. Determine the value of p^= the sample proportion of successes.

Short Answer

Expert verified

a. Hypothesis is rejected.

b. α=0.01:fail to reject the null hypothesis.and α=0.05:reject the null hypothesis

c.p^=0.57774

Step by step solution

01

Part (a) Step 1: Given Information

It is given that z=2.19

n=200

α=0.5

H0:p=0.5

Ha:p>0.5

02

Part (a) Step 2: Explanation

As z=2.19

P(x<z)=0.98574

P(x>z)=1-0.98574=0.014262

When Pvalue≤α, null hypothesis is rejected.

From above P=0.014262

P=0.014262<α, null hypothesis is rejected. H0:p=0.5

03

Part (b) Step 1: Given Information

It is given thatα=0.01,α=0.05

04

Part (b) Step 2: Explanation

Higher the significance level, higher is probability to reject null hypothesis.

As P=0.014262<0.5, so null hypothesis is rejected.

If α=0.01P=0.014262>0.01, null hypothesis is not rejected.

If α=0.05, P=0.014262>0.05, null hypothesis is not rejected.

Therefore,Pvalue changes with change in significance levels.

05

Part (c) Step 1: Given Information

It is given that n=200

p=0.5

z=2.19

06

Part (c) Step 2: Explanation

We know that z=p^-pp(1-p)n

Hence, 2.19=p^-0.50.5(1-0.5)200

2.19=p^-0.50.5(0.5)200

p^=(2.19×0.03535)+0.5

Therefore,p^=0.57774

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Most popular questions from this chapter

Walking to school Refer to Exercise 36.

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?

An opinion poll asks a random sample of adults whether they favor banning ownership of handguns by private citizens. A commentator believes that more than half of all adults favor such a ban. The null and alternative hypotheses you would use to test this claim are

а.H0:p∧=0.5;Ha:p∧>0.5H0:p^=0.5;Ha:p^>0.5.

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d. H0:p=0.5;Ha:p≠0.H0:p=0.5;Ha:p≠0.5.

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