Consider the accompanying time series.
a. Forecast the demand for each quarter in Year 4 using multiplicative decomposition.
b. Interpret the meaning of the seasonal components.
c. Calculate the MAD for this forecast.
Year 1
|
Year 2
|
Year 3
|
Quarter
|
Demand
|
Quarter
|
Demand
|
Quarter
|
Demand
|
1
|
28
|
1
|
28
|
1
|
27
|
2
|
20
|
2
|
15
|
2
|
15
|
3
|
24
|
3
|
20
|
3
|
19
|
4
|
10
|
4
|
10
|
4
|
6
|