Open the file DEATHS.TSM, but this time select Forecasting> Seasonal Holt-Winters. Specify 24 for the number of predicted values required, 12 for the period of the seasonality, and check the box...

Open the file DEATHS.TSM, but this time select Forecasting> Seasonal Holt-Winters. Specify 24 for the number of predicted values required, 12 for the period of the seasonality, and check the box marked Optimize Coefficients. Click OK, and the graph of the data and predicted values shown in Figure 9.3 will appear. Right-click on the graph and then on Info and you will see the numerical values of the predictors and the optimal values of the coefficientsα,β, andγ