data one;
  input trt pot plant weight;
  /* fungus:trt=1    placebo:trt=2 */
  cards;
1  1  1 20
1  1  2 10
1  2  3 18
1  2  4 13
1  3  5 25
1  3  6  5
1  4  7 27
1  4  8  4
1  5  9 16
1  5 10 14
2  6 11 31
2  6 12  9
2  7 13 25
2  7 14 15
2  8 15 21
2  8 16 20
2  9 17 28
2  9 18 12
2 10 19 22
2 10 20 17
;

proc glm;
  class trt;
  model weight=trt;
  output out=two residual=ehat predicted=yhat;
run;

proc univariate plot;
  var ehat;
run;

proc plot;
  plot ehat*yhat=pot;
run;