score ie
5%=1.96 /
if n=−9 then do; /
Find
n /
flag=1;
pz=probit(power); /
pz=cumulative z value for given
power
*/
function=(pz+pza)2; /
function=power
function /
n=ceil((function2(sd2))/(d
iff2));
end;
else if power=−9 then do; /
Find
power /
flag=2;
function=(n*diff*2)/(2(sd2
)) ;
pz=sqrt(function) −pza;
power=round (abs
(probnorm(pz)),.01);
end;
/
Print out
results /
title1 'COMPARISON OF TWO MEANS
(UNPAIRED DATA)';
proc print split='';
where flag=1; /
found
n /
id power;
var alpha diff sd n;
label n='CALCULATED VALUE
OF N PER GROUP' ;
title3 'Finding number of
subjects (n) per group' ;
run;
proc print split='';
where flag=2; /
found
power /
id alpha;
var diff sd n power;
label power='CALCULATED
VALUEOF POWER' ;
Appendix 357