The number of employees on the payroll at a food processing plant is recorded at the start of each month. These data are provided in the file S12_03.xlsx.
a. Is there a seasonal pattern in these data? If so, how do you explain this seasonal pattern? Also, if necessary, de-seasonalize these data using the ratio-to-moving-average method.
b. Forecast this time series for the first four months of the next year using the most appropriate method. Defend your choice of forecasting method.