Solve the following problem in class.

The quarterly demand for smartphones at a retailer is as show.

Year	Quarter	Demand
1	I	513
	II	932
	III	1509
	IV	1902
2	I	693
	II	1163
	III	1857
	IV	2469
3	I	846
	II	1439
	III	2271
	IV	3079
4	I	1070
	II	1751
	III	2785
	IV	3613

Forecast the quarterly demand for year 5 using the following models:

1. 4-week simple moving average.
2. Simple exponential smoothing with = 0.1
3. Trend adjusted exponential smoothing with = 0.1 and = 0.1
4. Linear Regression with seasonality/