The following 12 periods of actual demand are to be used to produce a double exponential smoothing forecast for period 13. Use a smoothing constant, α, equal to 0.25. Use 57 as the initial forecast values.
Perioda t
1…………………………………57
2…………………………………54
3…………………………………51
4…………………………………50
5…………………………………50
6…………………………………47
7…………………………………46
8…………………………………38
9…………………………………37
10…………………………………33
11…………………………………39
12………………………………35