data a1; 
   infile 'C:\Ageorge\Purdue\Stat512\Textdata\Ch01ta01.dat';
   input size hours;

data a2; size=65;  output;
         size=100; output;

data a3; set a1 a2; 

*The cli option generate prediction intervals for each x value;
proc reg data=a3; 
   model hours=size/cli; 
   id size; 
run;