The table below presents quarterly sales of shampoo, given in liters, over a three years period.

Year	Quarter	Sales	Forecast
1	Q1	266
1	Q2	143
1	Q3	183
1	Q4	119
2	Q1	194
2	Q2	161
2	Q3	175
2	Q4	140
3	Q1	339
3	Q2	250
3	Q3	301
3	Q4	221
4	Q1	?
4	Q2	?
4	Q3	?
4	Q4	?

1. Using Linear Regression with Seasonal Adjustment, what is your forecast of shampoo sales for January of year 4? Please show the detailed calculations.
2. After projecting your model in the past, calculate its Mean Absolute Percentage of Error (MAPE).