1.- Calculate alpha exponential smoothing method: 0.1; 0.5 and 0.9 2.- Calculate the sales levels for each period using moving average of order 2,4,6 and 8 3.- Calculate sales levels for each period using linear regression 4.- Calculate MAD 5.- Calculate PEMA 6.- What is the best method, based on MAD and PEMA calculations?

tiempo	Ventas
1	500
2	350
3	250
4	400
5	450
6	350
7	200
8	300
9	350
10	200
11	150
12	400
13	550
14	350
15	250
16	550
17	550
18	400
19	350
20	600
21	750
22	500
23	400
24	650
25	850
26	600
27	450
28	700