data bioremed;
  infile 'bioremed.txt';
  input trt $ conc;
  
/* print out the data to make sure we have the right stuff */
proc print;
  title 'Bioremediation example';
run;
            
/* draw side-by-side box plots (version 8) */
/* right now, this is commented out so will not produce any plot */
/*   to get the plot, delete the /* and  in the next three lines */
/* proc boxplot;
  plot conc*trt;
*/

/* do the usual t-test for equal means */  
proc ttest;
   class trt;
   var conc;
run;
     
/* do a wilcoxon rank sum test */
/* command to compute an exact test is commented out */
/*   delete the /* and  around the exact wilcoxon line */
/*   to compute the exact test.  Do this only if the sample sizes are small */
/*   the exact test can take a lot of computing time if N is not small */

proc npar1way wilcoxon;
   class trt;
   var conc ;
/*   exact wilcoxon;  */
   
run;