Problem 3-7

The following table contains the demand from the last 10 months:

MONTH	ACTUAL DEMAND
1	33
2	36
3	37
4	38
5	42
6	38
7	41
8	43
9	40
10	41

a. Calculate the single exponential smoothing forecast for these data using an of 0.20 and an initial forecast (F₁) of 33. (Round your intermediate calculations and answers to 2 decimal places.)

Month	Exponential Smoothing
1
2
3
4
5
6
7
8
9
10

b. Calculate the exponential smoothing with trend forecast for these data using an of 0.20, a of 0.20, an initial trend forecast (T₁) of 1.00, and an initial exponentially smoothed forecast (F₁) of 32. (Round your intermediate calculations and answers to 2 decimal places.)

Month	FITt
1
2
3
4
5
6
7
8
9
10

c-1. Calculate the mean absolute deviation (MAD) for the last nine months of forecasts. (Round your intermediate calculations and answers to 2 decimal places.)

	MAD
Single exponential smoothing forecast
Exponential smoothing with trend forecast

c-2. Which is best?

	Exponential smoothing with trend forecast
	Single exponential smoothing forecast

References

Worksheet