Use the data in GPA1 to answer these questions. It is a sample of Michigan State University undergraduates from the mid-1990s, and includes current college GPA, colGPA, and a binary variable indicating whether the student owned a personal computer (PC).

(i) How many students are in the sample? Find the average and highest college GPAs.

(ii) How many students owned their own PC?

(iii) Estimate the simple regression equation

colGPA = β₀ + β₁ PC = u

and report your estimates for β₀ and β₁. Interpret these estimates, including a discussion of the magnitudes.

(iv) What is the R-squared from the regression? What do you make of its magnitude?

(v) Does your finding in part (iii) imply that owning a PC has a causal effect on colGPA? Explain.