The wind-chill index is modeled by the function
W = 13.12 + 0.6215T - 11.37v^0.16 + 0.3965Tv^0.16
where T is the temperature (°C) and v is the wind speed (km/h). When T = 215°C and v = 30 km/h, by how much would you expect the apparent temperature W to drop if the actual temperature decreases by 1°C? What if the wind speed increases by 1 km/h?