(a) Compute four-week and five-week moving averages for the time series. 4-Week 5-Week Week Time Series Moving Moving Value Average Average Forecast Forecast 1 18 2 21 3 20 24 5 19 20.5 X 6 16 20.75 X 20.2 X 7 20 19.5 X 20.0 18 19.75 19.8 23 18.25 V 19.4 10 21 19.25 V 19.2 11 15 20.5 V 19.4 X 12 23 19.5 X 19.8 x (b) Compute the MSE for the four-week moving average forecasts. (Round your answer to two decimal places.) 9.36 X Compute the MSE for the five-week moving average forecasts. (Round your answer to two decimal places.) 8.09 X