d. Evaluate a seasonally adjusted trend forecasting model. What is the MAD? (Round your answers to 4 decimal places.)
Month Number	$ Sales (Millions	Period	Trend	Index	Forecast	Absolute Error
1	1578	1
2	837	2
3	829	3
4	819	4
5	888	5
6	823	6
7	797	7
8	1634	8
9	1174	9
10	825	10
11	852	11
12	1366	12
1	1496	13
2	801	14
3	817	15
4	839	16
5	891	17
6	814	18
7	779	19
8	1484	20
9	1107	21
10	799	22
11	813	23
12	1267	24
1	1381	25
2	819	26
3	844	27
4	820	28
5	896	29
6	837	30
7	811	31
8	1474	32
9	1096	33
10	851	34
11	878	35
12	1369	36
1	1254	37
2	776	38
3	795	39
					MAD=