27. Researchers at The Wharton School of Business have found that men and women shop for different reasons (Knowledge@Wharton, November 28, 2007). While women enjoy the shopping experience, men are on a mission to get the job done. Men do not shop as frequently but when they do, they make big purchases like expensive electronics. Recently a large electronics store in Chicago has started making eye-catching ads aimed to attract men's attention. In order to test the effectiveness of the strategy, the store records the number of daily male customers for 10 days before and after the ads appeared. Using the data shown in the accompanying table Day Before 1 2 3 4 5 6 7 8 9 10 After 38 45 49 54 62 84 77 42 44 48 Difference 42 -4 42 3 46 3 62 -8 70 -8 98 -14 88 -11 40 2 42 2 50 -2 a. Specify the competing hypotheses to test the effectiveness of the strategy to attract more male customers. b. Compute the value of the test statistic, assuming that the number of male customers follows a normal distributio c. Interpret the results of the test conducted at the 1% and the 10% levels of significance. ution