• 5.30

Emergency calls to Winter Park, Florida's 911 system for the past 24 weeks are as follows:

WEEK	CALLS	WEEK	CALLS	WEEK	CALLS
1	50	9	35	17	55
2	35	10	20	18	40
3	25	11	15	19	35
4	40	12	40	20	60
5	45	13	55	21	75
6	35	14	35	22	50
7	20	15	25	23	40
8	30	16	55	24	65

1. Compute the exponentially smoothed forecast of calls for each week. Assume an initial forecast of 50 calls in the first week, and use=0.1.What is the forecast for week 25?
2. Reforecast each period using=0.6.
3. Actual calls during week 25 were 85. Which smoothing constant provides a superior forecast?

• 5.31
  • How would the forecast for week 25 of the previous problem change if the initial forecast was 40 instead of 50? How would the forecast for week 25 change if the forecast for week 1 was assumed to be 60?