Question

Deseasonalize the data and use an appropriate technique to find the seasonally unadjusted forecasts for the next year. Include your results here, showing the deseasonalized data and the seasonally unadjusted forecasts.

Period	Year	Quarter	Sales
1	1	1	40
2	1	2	60
3	1	3	65
4	1	4	80
5	2	1	44
6	2	2	70
7	2	3	72
8	2	4	91
9	3	1	46
10	3	2	77
11	3	3	74
12	3	4	100
13	4	1	50
14	4	2	80
15	4	3	83
16	4	4	109

Answer 1

The calculations are:

				Centered
				Moving	Ratio to	Seasonal	Sales
t	Year	Quarter	Sales	Average	CMA	Indexes	Deseasonalized
1	1	1	40			0.653	61.2
2	1	2	60			1.031	58.2
3	1	3	65	61.750	1.053	1.026	63.3
4	1	4	80	63.500	1.260	1.290	62.0
5	2	1	44	65.625	0.670	0.653	67.4
6	2	2	70	67.875	1.031	1.031	67.9
7	2	3	72	69.500	1.036	1.026	70.2
8	2	4	91	70.625	1.288	1.290	70.5
9	3	1	46	71.750	0.641	0.653	70.4
10	3	2	77	73.125	1.053	1.031	74.7
11	3	3	74	74.750	0.990	1.026	72.1
12	3	4	100	75.625	1.322	1.290	77.5
13	4	1	50	77.125	0.648	0.653	76.5
14	4	2	80	79.375	1.008	1.031	77.6
15	4	3	83			1.026	80.9
16	4	4	109			1.290	84.5

The forecasts are:

Forecast

50.54341

79.74376

79.39294

99.81989