* prostate.txt;
/*********************************************************
 Data below gives the serum acid phosphatase levels
   in 20 prostate cancer patients whose cancer has spread
   to surrounding lymph nodes.
***********************************************************/
data prostate;
input acid;
datalines;
 0.56
 0.67
 0.99
 1.36
 0.82
 0.48
 0.51
 0.49
 0.84
 0.81
 0.76
 0.70
 0.78
 0.70
 0.67
 0.82
 0.67
 0.72
 0.89
 1.26
;
run;
proc print;
run;
proc means;
run;
data new;
set prostate;
d = acid - 0.645;
run;
proc means;
run;
proc ttest H0=0.645; * the default is H0=0;
  var acid;  
run;
proc ttest;
  var d;
run;