In a time series analysis, the additive model is used to forecast sales and the following seasonal variations
apply:
Quarter 1 2 3 4
Seasonal variation +5.8 -8.4 +10.2 ?
The seasonal variation for quarter 4 is:
A +7.6
B -8.1
C -7.6
D +8.1
How to get answer C
Let me get the answer .. Thank you