Children’s recall of TV ads. Marketing professors at Robert Morris and Kent State Universities examined children’s recall and recognition of television advertisements (Journal of Advertising, Spring 2006). 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. Following the viewing, the children were asked to recall 10 specific items from the ad. The number of the 10 items recalled correctly by each child is summarized in the table. The researchers theorized that “children who receive an audiovisual presentation will have the same level of mean recall of ad information as those who receive only the visual aspects of the ad.”

a. Set up the appropriate null and alternative hypotheses to test the researchers’ theory.

b. Find the value of the test statistic.

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

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

e. The researchers reported the p-value of the test as p-value = .542. Interpret this result.

f. What conditions are required for the inference to be valid?