data xrays;
input group error;
label error='percent error';
lines;
1 7.3
1 7.4
2 13.3
2 10.6
2 15.0
2 20.7
3 14.7
3 23.0
3 22.7
3 26.6
run;

proc format;
 value groupfm 1='senior staff'
                 2='junior staff'
                 3='residents';
run;

proc npar1way wilcoxon;
  class group;
  var error;
format group groupfm.;
title 'Kruskal-Wallis Test, One-Way ANOVA Using Ranks';
title2 'Data from P. 431 of Fisher and van Belle';
run;

proc plot;
 plot error*group;
 title 'Distribution of percent error for three groups'; 

run;