Consider the quarterly sales data for Worthington Health Club shown here $($also available on worksheet C$9$P$9$ in the OM$6$ Data workbook at OM$6$ Online$)$ Quarter Year $14215=12$ year $264414=28$

year $3103516=34$

year $4129722=50$

year $518101335=76$

a$.$ Develop a four period moving average model and comput MSE for your forecasts

b$.$ Find a good value of a for a single exponential smoothing model and compare your results to part a