The manager of the Petroco Service Station wants to forecast the demand for unleaded gasoline next month so that the proper number of gallons can be ordered from the distributor. The owner has accumulated the following data on demand for unleaded gasoline from sales during the past 10 months:
Month Gasoline ...... Demanded (gal.)
October ......... 800
November ......... 725
December ......... 630
January ......... 500
February ........ 645
March ......... 690
April .......... 730
May .......... 810
June ......... 1,200
July ........... 980
a. Compute an exponentially smoothed forecast, using an a value of .30.
b. Compute an adjusted exponentially smoothed forecast (with α = .30 and β = .20).
c. Compare the two forecasts by using MAPD and indicate which seems to be more accurate.