pls sir fast provide the ans

The table below shows the demand for construction equipment (excavators) in each of the last fourteen months. (a) Apply exponential smoothing for smoothing constants of 0.2, 0.4 and 0.8 to derive forecasts for the demand in month 15 (Initial forecast = 180). (b) Which of the above forecasts for month 15 do you prefer and why? What factors, not considered in the above calculations, might influence demand for the crane in month 15? Month 1 2 3 4 5 6 7 Demand 185 190 175 167 178 158 165 Month 8 9 10 11 12 13 14 Demand 155 163 150 145 140 182 188