The past sales history for Store 2 is provided in the table below. Using time se
ID: 426256 • Letter: T
Question
The past sales history for Store 2 is provided in the table below. Using time series trend projections (least squares regression analysis), forecast the demand for each month of the following year.
Month
Year
Period
Store 2
January
2016
1
72958
February
2016
2
83457
March
2016
3
85594
April
2016
4
99937
May
2016
5
87515
June
2016
6
73746
July
2016
7
66815
August
2016
8
69245
September
2016
9
42423
October
2016
10
30352
November
2016
11
67806
December
2016
12
65810
January
2017
13
58862
February
2017
14
68601
March
2017
15
99048
April
2017
16
101621
May
2017
17
99652
June
2017
18
88176
July
2017
19
76544
August
2017
20
56263
September
2017
21
41633
October
2017
22
51383
November
2017
23
68626
December
2017
24
61047
You have now moved through the next year and have the sales data available for this year:
Month
Year
Period
Store 2
January
2018
25
66835
February
2018
26
75846
March
2018
27
94947
April
2018
28
105905
May
2018
29
93258
June
2018
30
80414
July
2018
31
73313
August
2018
32
78439
September
2018
33
58743
October
2018
34
41542
November
2018
35
57414
December
2018
36
61038
Using your forecast sales and the actual sales for the current year, determine the MAD value for your forecast.
Month
Year
Period
Store 2
January
2016
1
72958
February
2016
2
83457
March
2016
3
85594
April
2016
4
99937
May
2016
5
87515
June
2016
6
73746
July
2016
7
66815
August
2016
8
69245
September
2016
9
42423
October
2016
10
30352
November
2016
11
67806
December
2016
12
65810
January
2017
13
58862
February
2017
14
68601
March
2017
15
99048
April
2017
16
101621
May
2017
17
99652
June
2017
18
88176
July
2017
19
76544
August
2017
20
56263
September
2017
21
41633
October
2017
22
51383
November
2017
23
68626
December
2017
24
61047
Explanation / Answer
Solution :
MAD = 16321.87
Month Year Period (t) Demand (Yt) t - tavg Yt - Yavg (t - tavg) * (Yt - Yavg) (t - tavg) * (t - tavg) Forecast Error Absolute Error Jan 2016 1 72958.00 -11.50 1411.58 -16233.21 132.25 Feb 2016 2 83457.00 -10.50 11910.58 -125061.13 110.25 Mar 2016 3 85594.00 -9.50 14047.58 -133452.04 90.25 Apr 2016 4 99937.00 -8.50 28390.58 -241319.96 72.25 May 2016 5 87515.00 -7.50 15968.58 -119764.38 56.25 Jun 2016 6 73746.00 -6.50 2199.58 -14297.29 42.25 Jul 2016 7 66815.00 -5.50 -4731.42 26022.79 30.25 Aug 2016 8 69245.00 -4.50 -2301.42 10356.38 20.25 Sep 2016 9 42423.00 -3.50 -29123.42 101931.96 12.25 Oct 2016 10 30352.00 -2.50 -41194.42 102986.04 6.25 Nov 2016 11 67806.00 -1.50 -3740.42 5610.63 2.25 Dec 2016 12 65810.00 -0.50 -5736.42 2868.21 0.25 Jan 2017 13 58862.00 0.50 -12684.42 -6342.21 0.25 Feb 2017 14 68601.00 1.50 -2945.42 -4418.13 2.25 Mar 2017 15 99048.00 2.50 27501.58 68753.96 6.25 Apr 2017 16 101621.00 3.50 30074.58 105261.04 12.25 May 2017 17 99652.00 4.50 28105.58 126475.13 20.25 Jun 2017 18 88176.00 5.50 16629.58 91462.71 30.25 Jul 2017 19 76544.00 6.50 4997.58 32484.29 42.25 Aug 2017 20 56263.00 7.50 -15283.42 -114625.63 56.25 Sep 2017 21 41633.00 8.50 -29913.42 -254264.04 72.25 Oct 2017 22 51383.00 9.50 -20163.42 -191552.46 90.25 Nov 2017 23 68626.00 10.50 -2920.42 -30664.38 110.25 Dec 2017 24 61047.00 11.50 -10499.42 -120743.29 132.25 Jan 2018 25 66835.00 63953.75 2881.25 2881.25 Feb 2018 26 75846.00 63346.34 12499.66 12499.66 Mar 2018 27 94947.00 62738.93 32208.07 32208.07 Apr 2018 28 105905.00 62131.51 43773.49 43773.49 May 2018 29 93258.00 61524.10 31733.90 31733.90 Jun 2018 30 80414.00 60916.69 19497.31 19497.31 Jul 2018 31 73313.00 60309.28 13003.72 13003.72 Aug 2018 32 78439.00 59701.86 18737.14 18737.14 Sep 2018 33 58743.00 59094.45 -351.45 351.45 Oct 2018 34 41542.00 58487.04 -16945.04 16945.04 Nov 2018 35 57414.00 57879.62 -465.62 465.62 Dec 2018 36 61038.00 57272.21 3765.79 3765.79 Total 300 1717114.00 -698525.00 1150.00 Average 12.5 71546.4167 Slope -607.41 Intercept 79139.08 Forecast MAD 16321.87Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.