Simulated data for the study is saved in the file. In Exercise 12.17, you fit the first-order model. E(y) = β0 + β1x1 + β2x2 + β3x3 + β4x4,where y = desire to have cosmetic surgery, x1 is a dummy variable for gender, x2 = level of self-esteem, x3 = level of body satisfaction, and x4 = impression of reality TV.
a. Check the data for multicollinearity. If you detect multicollinearity, what modifications to the model do you recommend?
b. Conduct a complete residual analysis for the model. Do you detect any violations of the assumptions? If so, what modifications to the model do you recommend?
For information: Refer to the Body Image: An International Journal of Research (March 2010) study of the influence of reality TV shows on one's desire to undergo cosmetic surgery, Exercise 12.17.