Refer to the annual OPEC oil import data, Exercise 14.21.
a. Use the exponentially smoothed (w = .9) series you constructed in Exercise 14.21a to forecast OPEC oil imports in 2015.
b. Forecast OPEC oil imports in 2015 using the Holt's forecasting model with smoothing constants w = .3 and v = .8.
c. Calculate the errors of the forecasts, parts a and b. Which method yields the smallest forecast error?