The town of Hillside has a surface reservoir that supplies water to the homes in the town’s central residential district. A committee of residents is concerned about the system’s capacity and wants to project future use. The town’s water department has promised to develop its best forecast of water use in the next two years. The department has collected quarterly data on water use (in millions of gallons) over the past decade, as shown in the following table:

a. Use the Holt-Winters method to estimate the quarterly water use for the coming eight quarters. Use smoothing parameters of a = 0.3, b = 0.4, and g = 0.5
b. For the forecasting problem in (a), which value of a achieves the minimum value of MSE, holding the other smoothing parameters constant?