The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who would have purchased a side curtain air bag if it had been available for an additional cost of $300. The manager believes from previous information that the proportion is 0.30. Suppose that a survey of 200 new compact-car owners is selected and 79 indicate that they would have purchased the side curtain air bags. If you were to conduct a test to determine whether there is evidence that the proportion is different from 0.30, which test would you use?
A) Z test of a population mean
B) Z test of a population proportion
C) t test of population mean
D) t test of a population proportion

Question

Quizplus · Accepted Answer

Since the question asks about the proportion of new compact-car owners who would have purchased the side curtain air bags, the appropriate test to use is a z-test of a population proportion. The sample size is reasonably large (n = 200) and the manager believes from previous information that the proportion is 0.30, so a z-test is appropriate.

The Marketing Manager for an Automobile Manufacturer Is Interested in Determining