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 19 21 28 38 26 30 36 24 25 30 ​a) The forecast for weeks 2 through 10 using exponential smoothing with alpha ​= 0.55 and a week 1 initial forecast of 19.0 are ​(round your responses to two decimal​ places): Week 1 2 3 4 5 6 7 8 9 10 Demand 19 21 28 38 26 30 36 24 25 30 Forecast 19.0 19.55 19. 119.55 19.55 30.99 30.99 28.25 28.25 28.66 28.66 32.70 32.70 25.71 25.71 25.987 25.87 nothing ​b) For the forecast developed using exponential smoothing ​(alpha ​= 0.55 and initial forecast 19.0​), the MAD​ = nothing sales ​(round your response to two decimal​ places). ​c) For the forecast developed using exponential smoothing ​(alpha ​= 0.55 and initial forecast 19.0​), the tracking signal​ = nothing ​(round your response to two decimal​ places).

Answer 1

week	actual	forecast	abs error	at -ft
1	19	19
2	21	19	2	2
3	28	20.1	7.9	7.9
4	38	24.445	13.555	13.555
5	26	31.90025	5.90025	-5.90025
6	30	28.65511	1.3448875	1.3448875
7	36	29.3948	6.605199375	6.605199375
8	24	33.02766	9.027660281	-9.02766028
9	25	28.06245	3.062447127	-3.06244713
10	30	26.3781	3.621898793	3.621898793
		MAD	5.890815897	17.03662826
			Tracking signal	2.892065982