Option ps=45 ls=80 nodate nonumber;


Data cracker;
	input sales pre treat store; X=pre-25;
	if treat=1 then I1=1; else if treat=2 then I1=0; else I1=-1;
	if treat=2 then I2=1; else if treat=1 then I2=0; else I2=-1;
Datalines;
  38  21  1  1
  39  26  1  2
  36  22  1  3
  45  28  1  4
  33  19  1  5
  43  34  2  1
  38  26  2  2
  38  29  2  3
  27  18  2  4
  34  25  2  5
  24  23  3  1
  32  29  3  2
  31  30  3  3
  21  16  3  4
  28  29  3  5
;
Proc plot;
	plot sales*pre=treat; run;

Proc GLM;
	class treat;
	model sales=treat X treat*X; run;

proc GLM;
	model sales=I1 I2 X ;
	output out=cracker P=yhat R=resid; run;

Proc plot;
	plot resid*yhat='R' / vref=0 ; run;

proc univariate normal plot;
        var resid; run;

proc rank normal=vw;
	var resid;
	ranks nscore;

proc plot ;
	plot resid*nscore='R';
	label nscore='Normal Score';

proc corr;
 	var resid nscore;
run;