data cd4; 
INPUT count;
datalines;
2610
2750
2420
2510
2540
2490
2680
run;                  

proc means;
var count;
title "The CD4 Count";
run;

proc means clm;
var count;
title "The CD4 Count with 95% confidence interval";
run;

proc means clm alpha=0.1;
var count;
title "The CD4 Count with 90% confidence interval";
run;

proc ttest H0=2500;
title "ttest for the population mean of CD4 counts with 95% confidence intervals"; 
run;

proc ttest H0=2500 alpha=0.1;
title "ttest for the population mean of CD4 counts with 90% confidence intervals"; 
run;