/* SAS code to analyze data on
   levels of lead in blood of 
   children (paired data)  */

data set1;
   input pair case control;
   diff = case-control; 
   datalines;
 1   38   16    
 2   23   18       
 3   41   18      
 4   18   24       
 5   37   19      
 6   36   11       
 7   23   10    
 8   62   15     
 9   31   16      
10   34   18       
11   24   18      
12   14   13       
13   21   19      
14   17   10       
15   16   16      
16   20   16       
17   15   24      
18   10   13      
19   45   9      
20   39   14      
21   22   21     
22   35   19      
23   49   7      
24   48   18      
25   44   19     
26   35   12       
27   43   11     
28   39   22      
29   43   25     
30   13   16      
31   73   13      
32   25   11 
33   27   13   
run;

proc univariate data=set1 normal;
  var diff;
  run;