/* module 6: problems 1, 2 */

/* 6.1 */
filename utility 'Utility.dat';
data one;
  infile utility;
  input date $ 1-6 telcost 9-15 fuelcost 17-22 emcost 25-29;
  totcost = telcost + fuelcost + emcost;
  year = substr(date,5,2);
   label telcost = Telephone Costs;
   label fuelcost = Fuel Costs;
   label emcost = Electricity Costs;
   label totcost = Total Costs;
run;
proc chart data=one;
  vbar telcost fuelcost emcost totcost;
   title "Utility Costs";
run;
* these four distributions are positively skewed;

/* 6.2 */
data two;
  set one;
  if 90 <= year <= 92;
run;
* utility data already sorted by year;
proc chart data=two;
  by year;
  vbar fuelcost / midpoints = 25 to 150 by 25;
   title "Utility Costs by Year, Fuel";
run;
proc chart data=two;
  by year;
  vbar totcost / midpoints = 100 to 300 by 40;
   title "Utility Costs by Year, Total";
run;
proc chart data=two;
  by year;
  vbar telcost / midpoints = 40 to 140 by 20;
   title "Utility Costs by Year, Phones";
run;
* The histograms for utility costs differ from year to year.;