DM 'LOG;CLEAR;OUT;CLEAR';

OPTIONS PS=60 LS=64 NODATE NONUMBER;

**********************************;
*** PERFORM TWO SAMPLE T-TEST  ***;
*** ON PAIRED DATA DIFFERENCES ***;
**********************************;

DATA in; INPUT before after y @@;
     diff = after-before;
CARDS;
 4 6  2   5 9 4   8 8 2    8 9 4   
 3 9  4   6 4 4   4 9 5    1 2 6
 5 6  1   6 9 0   8 7 4    2 4 3
 ;
PROC PRINT DATA=in;

PROC MEANS DATA=in N MEAN STDERR T PROBT CLM ALPHA=.10;
     VAR diff y;
TITLE  'Paired t-test to test if the';
TITLE2 'mean difference of before and'; 
TITLE3 'after measurements equals 0';
TITLE4 'and a one-sample t-test to test ';
TITLE5 'if the mean of y equals 0';
TITLE6 '(using PROC MEANS)';

RUN;