Use the data in GPA2.RAW for this exercise. (i) Using all 4,137 observations, estimate the equation
colgpa 5 b0 1 b1hsperc 1 b2sat 1 u and report the results in standard form.
(ii) Re estimate the equation in part (i), using the first 2,070 observations.
(iii) Find the ratio of the standard errors on hsperc from parts (i) and (ii). Compare this with the result from (5.10).