Statistics 512: Problem Set No. 7
Due October 24, 2008
For this problem use the CS dataset examined in previous problem sets, and use the model which
uses only HSM and HSE as explanatory variables to predict the response GPA. On Homework 6,
Problem 3 you examined some visual diagnostics (for your chosen model), which should have include
plots of Y vs. X, residuals, etc. Now, additionally examine other diagnostics such as studentized
and studentized-deleted residuals, Cook’s D, tolerance or vif, and partial residual plots. Explain any
problems such as outliers, highly influential observations or multicollinearity that these diagnostics
point out. (Do not include in your output any tables of values for all 224 individuals. Use plots
and verbal summaries instead. You may include values for a few selected individuals if you wish.)
1