Question

Chris is employed by a resort and sells timeshares. The following table shows the number of timeshare sales for Chris for each quarter over the past three years.

Period	Quarter	Sales		Period	Quarter	Sales
1	1	10		7	3	12
2	2	16		8	4	8
3	3	11		9	1	13
4	4	7		10	2	17
5	1	11		11	3	12
6	2	14		12	4	9

What is the sales forecast for Period 13 using multiplicative? decomposition? Round to one decimal place.

A.

14.9

B.

13.7

C.

14.3

D.

12.0

Answer 1

from abve :

t	sales	4-Qtr Moving Averages	Centrd Moving averages	seasonal irregular value	deseasonal index
1	10				14.71
2	16				18.39
3	11	11	11.125	0.989	16.18
4	7	11.25	11.000	0.636	16.28
5	11	10.75	10.875	1.011	16.18
6	14	11	11.125	1.258	16.09
7	12	11.25	11.500	1.043	17.65
8	8	11.75	12.125	0.660	18.60
9	13	12.5	12.500	1.040	19.12
10	17	12.5	12.625	1.347	19.54
11	12	12.75			17.65
12	9				20.93

applyinfg regression to deseasonal index:

slope =	0.379
intercept=	15.146

also seasonal index for quarter 1 =1.03

hence forecast for period 13=(0.379*13+15.146)*1.03=13.7

option B is correct