Sales for the past 12 months at XYZ Company are given here. 

Months	Sales ($ millions)	Months	Sales ($ millions)
January	20	July	53
February	24	August	62
March	27	September	54
April	31	October	36
May	37	November	32
June	47	December	29

n

Tasks: 

1. Use a 3-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. 

2. Use exponential smoothing with α = 0.6 to forecast the sales for the months April through December. Assume that the initial forecast for January was $22 million. Start error measurement in April. 

3. Compare the performance of the two methods by using the mean absolute deviation (MAD) as the performance criterion, with error measurement beginning in April. Which method would you recommend?