Would like help with C. in computing the weight moving average. and if possible D. as well

The Fastgro Fertilizer Company distributes fertilizer to various lawn and garden shops. The com pany must base its quarterly production schedule on a forecast of how many tons of fertilizer will be demanded from it. The company has gathered the following data for the past 3 years from its sales records: Year Quarter Demand for Fertilizer (tons) 1 2 1 2 3 4 5 6 7 8 9 10 105 150 93 121 140 170 105 150 150 170 110 130 3 11 12 a. Compute a three-quarter moving average forecast for quarters 4 through 13 and compute the forecast error for each quarter. b. Compute a five-quarter moving average forecast for quarters 6 through 13 and compute the forecast error for each quarter. c. Compute a weighted three-quarter moving average forecast, using weights of .50, .33, and .17 for the most recent, next most recent, and most distant data, respectively, and compute the forecast error for each quarter. d. Compare the forecasts developed in (a), (b), and (c), using cumulative error. Which forecast appears to be most accurate? Do any of them exhibit any bias? Weight Moving Average Year 1 2. 2 2 3 4. 5 6 17 18 19 20 Quarter 1 2 3 4 5 6 7 8 9 10 11 12 Forecast Error Absolute Forcast Erros Absolute Demand 3 months 3 months 3 month Error 5 months 5 months 5 month Error 105 150 93 121 116.00 5.00 5.00 140 121.33 18.67 18.67 170 118.00 52.00 52.00 121.80 48.20 48.2 105 143.67 -38.67 38.67 134.80 -29.80 29.8 150 138.33 11.67 11.67 125.80 24.20 24.2 150 141.67 8.33 8.33 137.20 12.80 12.8 170 135.00 35.00 35.00 143.00 27.00 27 110 156.67 -46.67 46.67 149.00 -39.00 39 130 143.33 -13.33 13.33 137.00 -7.00 7 136.67 142.00 32.00 25.48 36.40 26.86 3 3 13 21 total 22 23 26.86 MAD = MAPD = E = percent 36.40 24 25 26 27 28 29