Children’s recall of TV ads. Refer to the Journal of Advertising (Spring 2006) study of children’s recall of television advertisements, Exercise 8.103 (p. 491). Two groups of children were shown a 60-second commercial for Sunkist FunFruit Rock-n-Roll Shapes. One group (the A/V group) was shown the ad with both audio and video; the second group (the video only group) was shown only the video portion of the commercial. The number of 10 specific items from the ad recalled correctly by each child is shown in the table. Recall that the researchers theorized that children who receive an audiovisual presentation will have the same level of recall as those who receive only the visual aspects of the ad. Consider testing the researchers’ theory using the Wilcoxon rank sum test. A/V: 0 4 6 6 1 2 2 6 6 4 1 2 6 1 3 0 2 5 4 5 Video Only: 6 3 6 2 2 4 7 6 1 3 6 2 3 1 3 2 5 2 4 6 Source: R. H. Kolbe, M. Y. Hu, and J. K. Maher, “Children’s Recall of Television Ad Elements,” Journal of Advertising, Vol. 35. No. 1, 2006.

a. Set up the appropriate null and alternative hypotheses for the test.

b. Find the value of the test statistic.

c. Give the rejection region for a = .10.

d. Make the appropriate inference. What can you say about the researchers’ theory?