*
* Example 4.3 from p 128
*
open data gpa1.raw
data(format=free,org=columns) 1 141 age soph junior senior senior5 male campus business engineer colgpa $
 hsgpa act job19 job20 drive bike walk voluntr pc greek car siblings bgfriend clubs skipped alcohol gradmi $
 fathcoll mothcoll
*
linreg colgpa
# constant hsgpa act skipped