1. According to a Yankelovich poll, women spend an average of 19.1 hours shopping during the month of December, compared to 12.7 hours for men. Assuming that file XR11027 contains the survey data underlying these results, use the 0.01 level in examining whether the sample mean for women is significantly higher than that for men. Identify and interpret the p-value for the test.
Source: Anne R. Carey and Gary Visgaitis, "‘Tis the Season, Health," USA Today 1999 Snapshot Calendar, December 8.
2. When companies are designing a new product, one of the steps typically taken is to see how potential buyers react to a picture or prototype of the proposed product. The product-development team for a notebook computer com- pany has shown picture A to a large sample of potential buyers and picture B to another, asking each person to indi- cate what they "would expect to pay" for such a product. The data resulting from the two pictures are provided in file XR11028. Using the 0.05 level of significance, determine whether the prototypes might not really differ in terms of the price that potential buyers would expect to pay. Identify and interpret the p-value for the test. Construct and inter- pret the 95% confidence interval for the difference between the population means. Is the hypothesized difference (0.00) within the interval? Given the presence or absence of the 0.00 value within the interval, is this consistent with the findings of the hypothesis test?