Consider the sales data for Bell, Inc. given in Problem 2.

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 α = 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?

SALES ($ MILLIONS) 26 31 27 18 16 SALES ($MILLIONS MONTH MONTH January February March April May June 10 12 14 16 18 23 July August September October November December