An advertising agency has been hired by a manufacturer of pens to develop an advertising campaign for the upcoming holiday season. To prepare for this project, the research director decides to initiate a study of the effect of advertising on product perception. An experiment is designed to compare five different advertisements. Advertisement A: greatly undersells the pen's characteristics. Advertisement B: slightly undersells the pen's characteristics. Advertisement C: slightly oversells the pen's characteristics. Advertisement D: greatly oversells the pen's characteristics. Advertisement E: attempts to correctly stat the pen's characteristics. A sample of 25 adults respondents, taken from a larger focus group, is randomly assigned to the five advertisements (so that there are five respondents to each). After reading the advertisement and developing a sense of "product expectation," all respondents unknowingly receive the same pen to evaluate. The respondents are permitted to test the pen and the plausibility of the advertising copy. The respondents are then asked to rate the pen from 1 to 7 (lowest to highest) on the product characteristic scales of appearance, durability, and writing performance. Table Q5 shows the combined scores of three ratings (appearance, durability, and writing performance) for the 25 respondents. I aDIe V: LOIDmeu Scores oi uree raungs Advertisement A B D E 15 16 8. 5 12 18 17 7 6 19 17 21 10 13 18 19 16 15 11 12 19 19 14 9 17 (a) Determine whether there is evidence of a difference in the mean rating of the five advertisements at the 0.05 level of significance. (b) Identify the advertisement you should use and the advertisement you should avoid