* Cold1 Example;
* Test whether the number of colds is independent of the treatment
  using a chi-squared test for independence;

options linesize=70 nodate pageno=1;
data cold;
   input treatment $ cold count;
   datalines;
placebo 1  31
placebo 0 109
ascorb  1  17
ascorb  0 122
;

proc print;

proc freq;
   weight count;
   tables treatment * cold / chisq;

run;
quit;