/* chisquare_2way1.sas */
/* chisquare tests: homogeneity and independence */
/* ------------------------------------------- */   
/* chisquare test of homogeneity */
/* ------------------------------------------- */   
data cocaine;
   input treat $ relapse $ count;
   cards;
    desip   no   14
    desip   yes  10
    lithium no    6
    lithium yes  18
   ;
proc freq data=cocaine;
   tables treat*relapse / nocol nocum nopercent chisq cellchi2 deviation expected;
   weight count;
title 'cocaine treatment';
run;
/* ------------------------------------------- */
data attitude;
   input group $ attitude $ count;
   cards;
    rural  athletic  42
    rural  grades    57
    rural  popular   50
    suburb athletic  22
    suburb grades    87
    suburb popular   42
    urban  athletic  26
    urban  grades   103
    urban  popular   49
   ;
proc freq data=attitude;
   tables group*attitude /  nocol nocum nopercent chisq cellchi2 deviation expected;
   weight count;
title 'student attitudes';
run;
/* ------------------------------------------- */
/* chi-square test of independence */
/* ------------------------------------------- */   
data blood;
   input group $ type $ count;
   cards;
    H  A   2490
    HC A   2368
    HW A   4671
    W  A   50008
    H  AB  99
    HC AB  243
    HW AB  236
    W  AB  5001
    H  B   178
    HC B   568
    HW B   606
    W  B   16252
    H  O   1903
    HC O   2206
    HW O   4469
    W  O   53759
   ;
proc freq data=blood;
   tables type*group / chisq cellchi2 expected;
   weight count;
title 'blood types';
run;