In a survey 1864 out of 2246 randomly selected adults in the

In a survey, 1864 out of 2246 randomly selected adults in the United States said that texting while driving should be illegal (based on data from Zogby International). Consider a hypothesis test that uses a 0.05 significance level to test the claim that more than 80% of adults believe that texting while driving should be illegal.

a. What is the test statistic?
b. What is the critical value?
c. What is the P-value?
d. What is the conclusion?

Solution

Sample proportion = 1864/2246 = 0.8299

Alpha =0.05

Set up null and alternate as

H0: mu = 0.80

Ha: mu >0.80

Right tailed hypothesis test.

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std error = rt (p)(1-p)/n = 0.00844

Z statistic = 0.0299/0.00844 = 3.543

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p value = 0.000198

As p <0.05, we reject null hypothesis.

Conclusion is that more than 80% believe that texting while driving should be illegal.