Create the data set. REFLIB.JOBS contains average salary data for several categories of engineer. It also indicates the number of engineers in each category. 
data reflib.jobs;
   length eng $5;
   input eng dollars num;
   datalines;
Civil 27308 73273
Aero  29844 70192
Elec  22920 89382
Mech  32816 19601
Chem  28116 25541
Petro 18444 34833
;