Forecasts and actual sales of MP3 players at Just Say Music are as follows: Month Forecast Actual Sales March 150 170 April 220 229 May 205 192 June 256 241 July 250 238 August 260 210 September 270 225 October 280 179 a. Plot the data and provide insights about the time series. b. What is the forecast for November, using a two-period moving average? c. What is the forecast for November, using a three-period moving average? d. Compute MSE for the two- and three-period moving average models and compare your results. e. Find the best number of periods for the moving average model based on MSE.