Brooke, Samuel, and Jinshu use three different sales forecasting models. The following table shows their forecast errors.

*SAS Code needed*

a) Graphthese forecast errors for each model separately (3 plots) and one integrated plot including 3 forecast errors.

b)Which error pattern appear to be random?

c) Decide whether models Brooke, Samuel, and Jinshu adequately fit the data pattern characterizing sales. Explain your conclusion.

d)Calculate MAD and MSE for Brooke, Samuel, and Jinshu model.

Dataset

Week- Model Brook Forecast Error-Model Samuel

Forecast Error-Model JinshuForecast Error

1 25 15 -20

2 12 6 6

3 7 -10 15

4 5 -3 -10

5 3 12 8

6 0 4 -5

7 -4 -7 7

8 -11 -1 -8

9 -17 9 3

10 -21 7 10

11 -28 -12 -12

12 -34 -5 4

13 -21 17 -7

14 -13 3 9

15 -7 -9 19

16 -2 -3 -7

17 5 13 16

18 9 5 -6

19 15 -10 -9

20 19 -6 5