4.8 Using the data in Table 4-7, use Pegels' cell C-3 to model the data. First, examine the equations that go along with this method (see Table 4-10), then pick speci¯c values for the three parameters, and compute the one-ahead forecasts. Check the error statistics for the test period 10{24 and compare with the optimal results shown in Table 4-11. If you have access to a computer program to develop optimal values for the parameters, see if you can con¯rm the results in Table 4-11, for the appropriate method.