The file P12_02.xlsx contains the weekly sales at a local bookstore for each of the past 25 weeks.
a. Specify one or more promising auto regression models based on autocorrelations of this time series. Estimate each model with the available data. Which model provides the best fit to the data?
b. What general result emerges from your analysis in part a? In other words, what is the most appropriate auto regression model for any given random time series?
c. Use the best auto regression model from part a to forecast weekly sales at this bookstore for the next three weeks.