A market research consultant hired by the Pepsi-Cola Co. is interested in determining the proportion of consumers who favor Pepsi-Cola over Coke Classic in a particular urban location. A random sample of 250 consumers from the market under investigation is provided in the file P9-17.XLS:

a. Construct a 99% confidence interval for the proportion of all consumers in this market who prefer Pepsi over Coke. Interpret this confidence interval for Pepsi’s market researchers.

b. Does the confidence interval in part a support the claim made by one of Pepsi-Cola’s marketing managers that more than half of the consumers in this urban location favor Pepsi over Coke? Explain your answer.

¢. Comment on the sample size used by the market research consultant. Specifically, is the sample unnecessarily large? Why or why not?