***********************************************************************
* This is a program that illustrates the use of PROC POWER to         *
* calculate sample size when comparing two binomial proportions.      *
***********************************************************************;

proc power;
twosamplefreq groupweights=(1 1) groupps=(0.25 0.50) alpha=0.05 power=0.9
   test=Fisher sides=2 ntotal=.;
plot min=0.1 max=0.9;
title "Sample Size Calculation for Comparing Two Binomial Proportions (1:1 Allocation)"; 
run;

proc power;
twosamplefreq groupweights=(1 3) groupps=(0.25 0.50) alpha=0.05 power=0.9
   test=Fisher sides=2 ntotal=.;
plot min=0.1 max=0.9;
title "Sample Size Calculation for Comparing Two Binomial Proportions (3:1 Allocation)"; 
run;