* This is file SALTBACT.SAS ;
title 'Salty Bacteria';
DATA SALTBACT;
        infile saltbact;
        input W t S;
     I = t*S;
     LABEL W='Tritiated H20 production'
           t='time'
           S='NaCl concentration'
           I='interaction of Time and NaCl';
proc REG  data=saltbact;
        model W=S t I;
proc REG  data=saltbact;
        model W=S t;