/* module 7: problems 3, 5 */

/* 7.3 */
filename athlete 'athlete.dat';
data one;
  infile athlete;
  input systol 1-3 diastol 6-7 sex $ 10 active 13;
run;
proc sort data=one;
  by active;
run;
proc means data=one;
  by active;
run;
* Atheletic people have lower blood pressure;

/* 7.5 */
filename well 'Well#1.dat';
data two;
  infile well;
  input year 7-8 nitrate 11-15 zinc 18-22 tds 25-27;
  contam=0;
  if nitrate > .12 then contam=1;
  if zinc > .02 then contam=1;
  if tds > 516 then contam=1;
run;
* proc print data=two;
* run;
proc freq data=two;
  tables contam;
run;
* 9 not contaminated, 24 contaminated;
proc freq data=two;
  tables year*contam;
run;
* In 1990, 15 out of 15 readings showed contamination.;
* In 1991, 9 out of 18 readings showed contamination.;