Explain step by step please

Month Sales 1 22 2 21 3 24 4 30 5 25 6 25 7 33 8 40 9 36 10 39 Month Sales 11 50 12 55 13 44 14 48 15 55 16 47 17 61 18 58 19 55 20 60 a) Determine the one-step-ahead five-period moving average to compute forecasts of sales for months 6 to 20, and one-step ahead seven-period moving average to compute forecasts of sales for months 8 to 20. Which fits the date better for months 8 to 20? Explain b) Using a five-month moving average, determine the two-step-ahead forecasts of sales form months 15 to 20. c) Use an exponential smoothing approach with smoothing constant a = 0.2 to forecast sales for months 2 to 20. Change a = 0.1. Does this make the fit better or worse? Explain. d) What is the one-step-ahead five-period moving average forecast made at the end of month 18 for the sales in month 24