The file S12_61.xlsx contains monthly data on the number of nonfarm hires in the U.S. since 2000.
a. What evidence is there that seasonality is important in this series? Find seasonal indexes (by any method you like) and state briefly what they mean.
b. Forecast the next 12 months by using a linear trend on the seasonally adjusted data. State briefly the steps you use to obtain this type of forecast. Then give the final RMSE, MAPE, and forecast for the next month. Show numerically how you could replicate this forecast.