R:
x=c(16,40);  # placebo, test 
n=c(64,60);
prop.test(x,n);

SAS:
data respire;
   input treat $ outcome $ count ;
   cards;
   placebo f 16
   placebo u 48 
   test    f 40 
   test    u 20
   ; 
proc freq;
weight count;
tables treat*outcome/chisq expected fisher;  
run;