Consider the following time series data.

Week	1	2	3	4	5	6
Value	18	14	17	12	18	13

Using the average of all the historical data as a forecast for the next period, compute the following. (Round your answers to two decimal places.)

(a) mean absolute error MAE = 2.98

(b) mean squared error MSE = 10.24

(c) mean absolute percentage error MAPE =

(d)What is the forecast for week 7?

I have provided correct answers for parts a and b. Please show on excel how to calculate all parts. Show formulas