The following is a set of data for y, the amount of money (thousands of dollars) contributed to the alumni association at Virginia Tech by the Class of 1960, and x, the number of years following...

The following is a set of data for y, the amount of money (thousands of dollars) contributed to the alumni association at Virginia Tech by the Class of 1960, and x, the number of years following graduation:

(a) Fit a regression model of the type µ Y?x = 00 + 0lX.

(b) Fit a quadratic model of the type µ Y?x = ß o + ß1x + ß2x2.

(c) Determine which of the models in (a) or (b) is preferable. Use s2, R2, and the PRESS residuals to support your decision.