How do I do this in excel?

Directions:

Forecast sales for the first 12 months in 2005 using

1. The moving average method (number of time periods of your choice)

2. The exponential smoothing method

3. The time series method

For all 3 methods find the MAD and MAPE. Determine the most appropriate method for this set of data

Create a plot that shows actual demand and forecasted demand from all 3 methods

	Sales of shampoo over a 3yr period	Forecast	abs dev	MAD	% Error	MAPE
Month
2001-01	266.00
2001-02	145.90
2001-03	183.10
2001-04	119.30
2001-05	180.30
2001-06	168.50
2001-07	231.80
2001-08	224.50
2001-09	192.80
2001-10	122.90
2001-11	336.50
2001-12	185.90
2002-01	194.30
2002-02	149.50
2002-03	210.10
2002-04	273.30
2002-05	191.40
2002-06	287.00
2002-07	226.00
2002-08	303.60
2002-09	289.90
2002-10	421.60
2002-11	264.50
2002-12	342.30
2003-01	339.70
2003-02	440.40
2003-03	315.90
2003-04	439.30
2003-05	401.30
2003-06	437.40
2003-07	575.50
2003-08	407.60
2003-09	682.00
2003-10	475.30
2003-11	581.30
2003-12	646.90
2004-1	377.07
2004-2	475.63
2004-3	363.29
2004-4	465.66
2004-5	429.39
2004-6	468.02
2004-7	581.26
2004-8	411.68
2004-9	682.00
2004-10	503.82
2004-11	598.74
2004-12	666.31