Fit model (b). Examining the coefficients of this model is unpleasant because there are so many of them, and summaries either using graphs or using tests are required. We defer tests until the next...

Fit model (b). Examining the coefficients of this model is unpleasant because there are so many of them, and summaries either using graphs or using tests are required. We defer tests until the next chapter. Draw an effects plot for the year by region interaction and summarize the graph or graphs.