The Excel file Closing Stock Prices provides data for four stocks and the Dow Jones Industrial Average over a one-month period.

a. Develop a spreadsheet model for forecasting each of the stock prices using simple exponential smoothing with a smoothing constant of 0.3.

b. Compare your results to the output from Excels Data Analysis tool.

c. Compute MAD, MSE, and MAPE.

d. Does a smoothing constant of 0.1 or 0.5 yield better results?

Closing Stock Prices
Date	IBM	INTC	CSCO	GE	DJ Industrials
9/3/2010	127.58	18.43	21.04	15.392	10447.93
9/7/2010	125.95	18.12	20.58	15.44	10340.69
9/8/2010	126.08	17.9	20.64	15.7	10387.01
9/9/2010	126.36	18	20.61	15.91	10415.24
9/10/2010	127.99	17.97	20.62	15.98	10462.77
9/13/2010	129.61	18.557	21.26	16.25	10544.13
9/14/2010	128.85	18.74	21.45	16.16	10526.49
9/15/2010	129.43	18.72	21.59	16.34	10572.73
9/16/2010	129.67	18.97	21.93	16.23	10594.83
9/17/2010	130.19	18.81	21.863	16.29	10607.85
9/20/2010	131.79	18.93	21.75	16.55	10753.62
9/21/2010	131.98	19.14	21.64	16.52	10761.03
9/22/2010	132.57	19.01	21.67	16.5	10739.31
9/23/2010	131.67	18.98	21.53	16.14	10662.42
9/24/2010	134.11	19.423	22.09	16.66	10860.26
9/27/2010	134.65	19.235	22.11	16.43	10812.04
9/28/2010	134.89	19.505	21.863	16.44	10858.14
9/29/2010	135.48	19.24	21.87	16.36	10835.28
9/30/2010	134.14	19.2	21.9	16.25	10788.05
10/1/2010	135.64	19.32	21.91	16.36	10829.68