please include all the steps in details.show calculations. no excel work please

The sales data for Victoria Gifts is given: Use 3 period moving average to forecast for periods 4 through 10. Using weights of 0.2, 0.3, and 0.4, forecast the demand for period 4 through 10. With Alpha = 0.1, and initial forecast of 149, forecast through period 10 using simple exponential smoothing