Question

Sales of tablet computers at Ted​ Glickman's electronics store in​ Washington, D.C., over the past 10 weeks are shown in the table​ below:                                                                                                                     Week 1 2 3 4 5 6 7 8 9 10 Demand 21 21 28 36 26 29 35 20 25 30 ​a)

The forecast for weeks 2 through 10 using exponential smoothing with alpha ​= 0.55 and a week 1 initial forecast of 21.0 are ​(round your responses to two decimal​ places): Week 1 2 3 4 5 6 7 8 9 10

Demand 21 21 28 36 26 29 35 20 25 30

Forecast 21.0 21 21 24.85 30.98 28.24 28.65 32.14 25.46 25.20 ​

b) For the forecast developed using exponential smoothing ​(alpha ​= 0.55 and initial forecast 21.0​), the MAD​ = nothing sales ​(round your response to two decimal​ places).

C. Tracking signal

Answer 1

Week	Demand	Forecast	Abs Deviation	Deviation
1	21	21	0	0
2	21	21	0	0
3	28	21	7	7
4	36	24.85	11.15	11.15
5	26	30.98	4.98	-4.9825
6	29	28.24	0.76	0.757875
7	35	28.66	6.34	6.341044
8	20	32.15	12.15	-12.1465
9	25	25.47	0.47	-0.46594
10	30	25.21	4.79	4.790328
SUM			47.63	12.44

MAD = 47.63 / 10 = 4.763

Tracking Signal = 12.44 / 4.763 = 2.61