Refer to the Journal of Applied Psychology (June 2002) study of recall of television commercials, presented in Exercise 10.33 (p. 495). Participants were assigned to watch one of three types of TV programs, with nine commercials embedded in each show. Group V watched a TV program with a violent-content code rating, Group S viewed a show with a sex-content code rating, and Group N watched a neutral TV program with neither a V nor an S rating. The dependent variable measured for each participant was the score (y) on his or her recall of the brand names mentioned in the commercial messages, with scores ranging from 0 (no brands recalled) to 9 (all brands recalled). The data are saved in the TVADRECALL file.

a. Write a model for E (y) as a function of viewer group.

b. Fit the model you wrote in part a to the data saved in the TVADRECALL file. Give the least squares prediction equation.

c. Conduct a test of overall model utility at α = .01. Interpret the results. Show that the results agree with the analysis performed in Exercise 10.33.

d. The sample mean recall scores for the three groups were y-barV = 2.08, y-barS = 1.71, and y-barN = 3.17. Show how to find these sample means by using only the β-estimates obtained in part b.