ABC Corporation has given you the following information sales history.

Quarter Demand

____________ 2012 2013 2016

1 10 12 17

2 20 25 32

3 15 17 19

4 9 10 15

a). Plot the quarterly sales data for each year

b). What are the trend and the seasonal index for each quarter?

c). Assume exponential, trend and seasonal smoothing with = 0.2, = 0.3 and = 0.4. Forecast the

demand for the 2nd and 3rd quarter of 2017.

If actual demand during the 1 quarter of 2017 is 50, find the updated seasonality index, level and trend

for 1 quarter 2017 and forecast the second quarter of 2017.