URGENT PLEASE

4. The sales (in millions of dollars) for an 18-month period are as follows. Month 1 2 Month 9 10 3 4 Sales 600 775 600 650 700 800 550 775 Sales 600 775 600 575 625 650 600 11 12 13 14 15 5 6 7 8 a. Compare a three-month moving average forecast with an exponential smoothing forecast. Use a = 0.1. Which provides the better forecasts based on MSE? b. Find the forecast for the next month using the best forecast method