data fw09p03; title 'CHAPTER 9, PROBLEM 3';
input  OBS    A $  C $  Y ;
cards;
  1    2    1     3.6
  2    2    1     4.5
  3    2    1     3.9
  4    2    2     7.1
  5    2    2     7.3
  6    2    2     5.0
  7    2    3     8.2
  8    2    3     6.0
  9    2    3     9.8
 10    4    1     7.7
 11    4    1     7.7
 12    4    1     7.7
 13    4    2     9.8
 14    4    2    10.0
 15    4    2     8.6
 16    4    3    10.3
 17    4    3    12.3
 18    4    3     8.5
 19    6    1     6.5
 20    6    1     8.5
 21    6    1     6.3
 22    6    2     8.0
 23    6    2     6.5
 24    6    2     9.6
 25    6    3     6.0
 26    6    3     6.9
 27    6    3     6.1