/*BPS problems 20.6 and 20.8*/
options ls = 80;
  data NCSU;
  input Grade ECHs Count @@;
  datalines;
   1 1 11	  1 2 68  	1 3 3
   2 1 9 	  2 2 23    2 3 5
   ;
proc freq data=NCSU;
      weight Count;
      tables Grade*ECHs/expected chisq;
run;
quit;