Retailers pay close attention to holiday sales during the Thanksgiving weekend each year. To monitor these sales, a random sample of shoppers was selected in 2012 and again in 2013. The amount of money each shopper spent in stores and on Web sites was recorded. These data can be found in the Excel file holiday sales. xlsx. Assume that the population variances for the amounts spent during this weekend in the two years are equal.

a. Using α = 0.10, perform a hypothesis test to determine if the average amounts spent on holiday shopping during this weekend differ between the two years.

b. Approximate the p value using Table 5 in Appendix A and interpret the results.

c. Construct a 90% confidence interval to estimate the average difference in the amounts spent by holiday shoppers between the two years. Interpret your result.

d. Verify your results using PHStat or Excel.

e. Identify the p value and interpret the result.

f. What assumptions need to be made in order to perform this procedure?