Question: A professor obtains SAT scores and freshman GPA s for a group of n = 15 college students. The SAT scores have a mean M = 580 with SS = 22,400, and the GPA s have a mean of 3.10 with SS = 1.26 and SP = 84.

a. Find the regression equation for predicting GPA from SAT scores.

b. What percentage of the variance in GPA is accounted for by the regression

equation ?(Compute the correlation r , then find r².)

c. Does the regression equation account for a significant portion of the variance in GPA ?

Use α = .05. to evaluate the F-ratio.