***please help to solve using the Winters method only***

using the Winters method please help to find the forecast four period ahead for the following. QUESTION 6 A company has experienced the following quarterly sales for the past eight quarters Quarter Demand Quarter Demand (year (year 1) 2) 1 10 5 12 2 22 6 26 3 26 7 30 4 19 8 22 Considering the following values for the intercept, slope, seasonal factors, and smoothing constants Go= 2.3362, So=29.36, C-3= 0.5330, c-2=1.1752, C-1= 1.2825, C026.9203 a=0.2, v=0.1. 0.1 Forecast four period ahead demand at time t=0 (t=O=present, period 8) 15.12