Weekly sales of lamps at Cubicle Suppliers are shown in the table below.

i).Compute a three-period moving average of sales.

ii).Compute an exponential smoothing forecast (with alpha = 0.2), note the initial forecast is 18.

iii).Compute a three-period weighted moving average of sales, with weights of 3 for the most recent, 2 for the second most recent and 1 for the third most recent.

iv) Compute MAD for each forecast.

v).Which model is more accurate?

vi).Forecast week 8 with the most accurate method.

Week Sales(cased 3MA |error| Expo. |error| 3M Wtg MA |error|

(alpha = 0.2)

1 17

2 21

3 27

4 31

5 19

6 17

7 21

8