Chapter 11 Times Series 4814 Type F1 in the By Changing Cells text box to indicate that you want to
change the value of F1, the smoothing constant, in order to minimize
cell F2.
Because the exponential smoothing constant can take on only val-
ues between 0 and 1, you have to add some constraints to the values
that the Solver will investigate.
5 Click the Add button.
6 Type F1 in the Cell Reference text box, select * 5 from the Constraint
drop-down list, type 1 in the Constraint text box, and then click Add.
7 Type F1 in the Cell Reference text box, select + 5 from the Constraint
drop-down list, type 0 in the Constraint text box, and then click Add.
8 Click Cancel to return to the Solver Parameters dialog text box. The
completed Solver Parameters dialog box should look like Figure 11-36.Figure 11-36
The Solver
Parameters
dialog box
9 Click Solve.
The Solver now determines the optimal value for the smoothing
constant (at least in terms of minimizing the mean square error).
When the Solver is fi nished, it will prompt you either to keep the
Solver solution or to restore the original values.
10 Click OK to keep the solution.The Solver returns a value of 0.028792 (cell F1) for the smoothing con-
stant, resulting in a mean square error of 23.99456 (cell F2). This is the
optimal value for the smoothing constant.