Refer to the Body Image: An International Journal of Research (Mar. 2010) study of the impact of reality TV shows on a college student's decision to undergo cosmetic surgery, Exercise 12.25 (p. 672). Consider the interaction model E(y) = β0 + β1x1 + β2x4 + β3x1x4, where y = desire to have cosmetic surgery (25-point scale), x1 = {1 if male, 0 if female}, and x4 = impression of reality TV (7-point scale). The model was fit to the data and the resulting SAS printout appears at the bottom of the page.
a. Give the least squares prediction equation.
b. Find the predicted level of desire (y) for a male college student with an impression-of-reality-TV-scale score of 5.
c. Conduct a test of overall model adequacy. Use α = .10.
d. Give a practical interpretation of R2α.
e. Give a practical interpretation of s.
f. Conduct a test (at α = .10) to determine if gender (x1) and impression of reality TV show (x4) interact in the prediction of level of desire for cosmetic surgery (y).
g. Give an estimate of the change in desire (y) for every 1-point increase in impression of reality TV show (x4) for female students.
h. Repeat part g for male students.