Consider the American Express closing price data from Problem 22 in the file P16_22.xlsx.

a. Create a time series chart of the data. Based on what you see, which of the exponential smoothing models do you think will provide the best forecasting model? Why?

b. Use Holt’s exponential smoothing to forecast these data, using the smoothing constants


0.1.

c. Repeat part

b, searching for the smoothing constants that make RMSE as small as possible. Does it make much of an improvement over the result in part b?