The following table presents the starting annual salaries (SAL) of a group of 30 college graduates who have recently entered the job market, along with their cumulative grade-point averages (CGPA).
a. Determine the least-squares estimates of the slope and intercept for the straight-line regression of SAL (Y) on CGPA (X).Draw the estimated line on the accompanying scatter diagram, and comment on the fit.
b. Are any of the assumptions for straight-line regression clearly not satisfied in this example?

c. Obtain a 95% confidence interval for β1.
d. Would you reject the null hypothesis H0: β1 = 4,000 at the α = .05 level?
e. Find and graph 95% confidence and prediction bands.
f. Would you reject the hypothesis H0: µY|X = 11,500 at X0 = 2.75?