In: Statistics and Probability
The sales of vacuum cleaners at Lowenthal’s Industrial Supply over the last thirteen months are given below.
Month |
Sales |
Month |
Sales |
1 |
12 |
8 |
14 |
2 |
14 |
9 |
17 |
3 |
16 |
10 |
12 |
4 |
10 |
11 |
14 |
5 |
15 |
12 |
16 |
6 |
17 |
13 |
11 |
7 |
11 |
a) Use a weighted moving average for three periods to forecast sales for next month. Use a weight of 3 for the most recent period, 2 for the middle period, and 1 for the third previous period. What is the forecasted number of vacuum sales for next month?
b) Use a weighted moving average for three periods to forecast sales for next month. Use a weight of 4 for the most recent period, 3 for the middle period and 2 for the third previous period. What is the forecasted number of vacuum sales for next month?
c) Which forecast of sales should Lowenthal use and why?
a)
MAD = 2.73
MSE = 9.63
MAPE = 21.55%
b)
MAD = 2.54
MSE = 8.45
MAPE = 20.04%
c)
MSE part a > MSE part b
Part b forecast of sales should Lowenthal use