1. What is the appropriate Box-Jenkins model to use on the original data?
2. What are your forecasts for the first four weeks of January 1983?
3. How do these forecasts compare with actual sales?
4. How does your Box-Jenkins model compare to the regression models used in Chapter 8?
5. Would you use the same Box-Jenkins model if the new data were combined with the old data?
This case refers to the sales data and situation for the restaurant discussed in Case 8-3. Jim Price has now completed a course in forecasting and is anxious to apply the Box-Jenkins methodology to the restaurant sales data. These data, shown in Table 9-17A, begin with the week ending Sunday, January 4, 1981, and continue through the week ending Sunday, December 26,1982. Table 9-17B contains new data for the week ending January 2, 1983, through the week ending October 30, 1983.