3.12 Is the relationship between experience and wages constant over one's lifetime? To investigate we will fit a quadratic model using the data file cps4_small.dat, which contains 1,000 observations on hourly wage rates, experience and other variables from the 2008 Current Population Survey (CPS). (a) Create a new variable called EXPERBO = EXPER 30. Construct a scatter diagram with WAGE on the vertical axis and EXPER30 on the horizontal axis. Are any patterns evident? (b) Estimate by least squares the quadratic model WAGE = y1 + yZ(EXPER30)2 + 3 Are the coefficient estimates statistically significant? Test the null hypothesis that yz Z 0 against the alternative that y;