a. Plot the data presented in Exercise 7 to examine the possible existence of trend and seasonality in the data.
b. Prepare four separate smoothing models to examine the full-service restaurant sales data using the monthly data.
1. A simple smoothing model
2. Holt's model
3. Winters' model
c. Examine the accuracy of each model by calculating the root-mean-squared error for each during the historical period. Explain carefully what characteristics of the original data led one of these models to minimize the root-mean-squared error.