Chapter 8.4, Problem 11E

For Exercises 5 through 20, perform each of the following steps.

a. State the hypotheses and identify the claim.

b. Find the critical value(s).

c. Compute the test value.

d. Make the decision.

e. Summarize the results.

Use the traditional method of hypothesis testing unless otherwise specified.

11. Automobiles Purchased An automobile owner found that 20 years ago, 76% of Americans said that they would prefer to purchase an American automobile. He believes that the number is much less than 76% today. He selected a random sample of 56 Americans and found that 38 said that they would prefer an American automobile. Can it be concluded that the percentage today is less than 76%? At α = 0.01, is he correct?

Source: Opinion Research Corporation.