* SAS code to fit Panther data from Exercise 6.7;
 options linesize=70;

 data mpanther;
 input age ratio @@;
 y = log(ratio);
     agebar = 4.875 ;
           x = age - agebar;
           x2 = x*x;
 cards;
  1  0.42   2  0.39   2  0.54
  3  0.65   3  0.75 
  9  0.56   9  0.53  10  0.48
 
 * Use 2 MODEL statements;
 * 1st for Full model, and 2nd for Reduced model;

 proc reg;
    model y = x x2;    * Fit quadratic model;
    model y = x;       * Fit reduced linear model;
 run;