Question: Using the data from Problem, forecast the average gasoline price for each month in year 4 by using the multiplicative decomposition model. What is the MAPE value for this model?
Problem: The average price per gallon of gasoline in major U.S. cities for each month during a three-year period are shown in the following table:
(a) Using exponential smoothing with a = 0.45, what is the gasoline price forecast for January of year 4?
(b) What is the linear trend equation that best fits the data? Forecast the average gasoline price for January of year 4 by using this equation.
(c) Which method is more accurate?