Consider the following sales data for Bell, Inc.

Month Sales ($ Millions)

Jan. 10

Feb. 12

March 14

April 16

May 18

June 23

July 26

Aug. 31

Sept. 27

Oct. 18

Nov. 16

Dec. 14

a. Use a three-month weighted moving average to forecast the sales for the months April through December. Use weights of (3/6), (2/6), and (1/6), giving more weight to more recent data.

b. Use exponential smoothing with = 0.30 to forecast the sales for the months April through December. The forecast for January was $12 million.

c. Compare the performance of the two methods by using the bias and MAD as the performance criteria. Which performance method is the most reasonable? Why?