Suppose that you are using exponential smoothing with a = 0.5 and your initial forecast 5 months ago was for 100 units. If the actual demand last month was 0 units, which of the following is definitely true?
a) The forecast for this month should be 0.
b) The model blew up. You can't use exponential smoothing anymore.
c) The forecast for last month was 0.
d) The forecast for this month should be 50.
e) We need more information to determine this month's forecast.
Answer: e) We need more information to determine this month's forecast.