(a) Compute four-week and five-week moving averages for the time series. (b) Compute the MSE for the four-week moving average forecasts. (Round your answer to two decimal places.) 9.06x Compute the MSE for the five-week moving average forecasts. (Round your answer to two decimal places.) (c) What appears to be the best number of weeks of past data (three, four, or five) to use in the moving averoge computation? MSE for the three-week moving average is 9.06. Three weeks appears to be best, bocause the three-week moving average provides the smallest MSE. Three weeks appears to be best, because the three-week moving average provides the largest MSE. Four weeks appears to be best, because the four-week moving average provides the smallest MSE. Five weeks appears to be best, berause the five-week moving average provides the smallest MSE. None appear better then the others, because they all provide the same MSE