data fw05p13; title 'chapter 5, exercises 13 and 14';
input PAT  DRUG $ HALFLIFE ;
cards;
   1  G     1.60
   2  A     2.50
   3  G     1.90
   4  G     2.30
   5  A     2.20
   6  A     1.60
   7  A     1.30
   8  A     1.20
   9  G     1.80
  10  G     2.50
  11  A     1.60
  12  A     2.20
  13  A     2.20
  14  G     1.70
  15  A     2.60
  16  A     1.00
  17  G     2.86
  18  A     1.50
  19  A     3.15
  20  A     1.44
  21  A     1.26
  22  A     1.98
  23  A     1.98
  24  A     1.87
  25  G     2.89
  26  A     2.31
  27  A     1.40
  28  A     2.48
  29  G     1.98
  30  G     1.93
  31  G     1.80
  32  G     1.70
  33  G     1.60
  34  G     2.20
  35  G     2.20
  36  G     2.40
  37  G     1.70
  38  G     2.00
  39  G     1.40
  40  G     1.90
  41  G     2.00
  42  A     2.80
  43  A     0.69
proc sort; by drug;
proc means sum mean std css ; by drug; var halflife;
proc ttest; class drug; var halflife;
run;