options ls=79 ps=50 nocenter;

data bacteria;
   infile 'bactroom.dat' firstobs=2;
   input bact $ temp $ run $ bill code trt;
proc plot;
   plot bill*trt=run;
   plot bill*temp=bact;

* interaction plots with LSD;
proc glm;
   class bact temp;
   model bill =  bact temp bact*temp / ss1;
   lsmeans bact*temp / stderr out=lsm;
proc plot data=lsm;
   plot lsmean*temp=bact;
run;