Xiaohong's family used 68 kwh of electricity last month and paid 37.4 yuan. According to this calculation, Aunt Li's family paid 53.9 yuan last month How many kilowatts of electricity did her family use last month?

Xiaohong's family used 68 kwh of electricity last month and paid 37.4 yuan. According to this calculation, Aunt Li's family paid 53.9 yuan last month How many kilowatts of electricity did her family use last month?

53.9÷（37.4÷68）
=53.9÷0.55
=98 (KWH)

The standard of electricity charge for residents in a city is as follows: the electricity price is 0.53 yuan / kWh when the monthly electricity consumption is less than 50 kWh (including 50 KWH); the electricity price is 0.56 yuan / kWh when the monthly electricity consumption is more than 50 kWh and less than 200 kWh (including 200 KWH); the electricity price is 0.63 yuan / kWh when the monthly electricity consumption is more than 200 kwh
(1) Suppose that the monthly electricity fee payable is y yuan, and the function between Y yuan and X kwh is written
(2) Find the function values when x = 45120230, and explain their practical significance
(3) If the electricity charge of a month is 99.3 yuan, how much is the electricity consumption of this month

(1)y=0.53x (x=