Earning Power a College's Job Placement Office Collected Data About $$r = 0.72$$

Earning power A college's job placement office collected data about students' GPAs and
the salaries they earned in their first jobs after graduation. The mean GPA was 2.9 with a
standard deviation of 0.4. Starting salaries had a mean of $47,200 with a SD of $8500. The
correlation between the two variables was $$r = 0.72$$
The association appeared to be linear in
the scatterplot. (Show work)
a. Write an equation of the model that can predict salary based on GPA.
b. Do you think these predictions will be reliable? Explain.
c. Your brother just graduated from that college with a GPA of 3.30. He tells you that based
on this model the residual for his pay is -$1880. What salary is he earning?