(2) 40W21.20 yuan; Such as 100 watt is 54.50 yuan; 250 watts 142.00 yuan.
(3) Because 50 kWh is 26.50 Yuan and 200 kWh 1 10.50 Yuan, the electricity charge of 96.50 Yuan is below 200 watts and above 50 watts. If the electricity consumption is (50+X) watts, then 50*0.53+0.56X=96.50, x.