The file P16_33.xlsx contains weekly data for the S&P 500 stock index from the beginning of 2002 to mid2003. (It was downloaded from the Yahoo! site. You can follow the hyperlink in the file to obtain...

The file P16_33.xlsx contains weekly data for the S&P 500 stock index from the beginning of 2002 to mid2003. (It was downloaded from the Yahoo! site. You can follow the hyperlink in the file to obtain more recent data if you like.) In particular, the file lists closing prices in column H, adjusted for dividends and stock splits.

a. Create a time series plot of the adjusted closing prices. Does it look like moving averages and/or simple exponential smoothing will perform well on this series?

b. Run moving averages on the adjusted closing prices, experimenting with the span. Which span appears to work best? Report the MAE, RMSE, and MAPE values, and show a graph of the series with the forecasts superimposed, for the best span.

c. Run simple exponential smoothing on the adjusted closing prices, experimenting with the smoothing constant. Which smoothing constant appears to work best? Report the MAE, RMSE, and MAPE values, and show a graph of the series with the forecasts superimposed, for the best smoothing constant.