* 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

 proc genmod;
        model y = x x2 / dist=normal
                       link=identity
                       dscale
                       covb;
 run;