Exercise 12.150 referred to a Gallup survey conducted in October that asked shoppers how much they expect to spend on Christmas presents. A follow-up survey in November of the same year asked a different sample of shoppers what they expect to spend on Christmas presents. If the November expectation is less than the October expectation, this may be bad news for retailers who depend on Christmas shopping. Do these data provide sufficient evidence to infer that this is bad news for retailers?

Data from in Exercise 12.150

Christmas shopping represents a major of revenue for retailers. A successful season usually means that the retailer will be profitable for the year. A Gallup survey conducted in October asked shoppers how much they expect to spend on Christmas presents. Assume that there are 25 million Christmas shoppers. Calculate a confidence interval estimate of the total amount expected to spend for presents.