Question: Suppose that an electronics company has the monthly sales shown below. They want to develop forecasts using a time series regression model, a trend enhanced exponential smoothing model using a = 0.30 and ∂ = 0.40, and then seasonally adjust these two models using the regression forecasts as the base for calculating the seasonal indexes. Finally, they want to determine which forecasting model fits the data better, and use this model to predict sales for the next six months.
