My family used 85 kwh of electricity last month, and the electricity charge was 47.6 yuan. My family used 50 kwh last month, how much is the electricity charge? Proportional solution Is it a positive ratio or a housing ratio

Positive proportion
The electricity charge is x yuan
Then 85:47.6 = 50: X
x=47.6×50÷85
x=28
So the electricity charge is 28 yuan

Xiao Ming's family used 50 kwh of electricity last month, and the electricity charge was 30 yuan

Conditions: Xiaoming's electricity consumption last month was 50 kwh, and the electricity charge was 30 yuan
The question can be designed as: how much is the electricity charge for Xiaoming's 100 kilowatt hours this month?
When the electricity charge per kilowatt hour is fixed, the electricity charge is directly proportional to the electricity consumption
You can set the electricity charge for this month as X Yuan
Then, according to the proportional relationship, the following equation can be formulated:
50:30=100：x
The solution is x = 60
So the electricity charge is 60 yuan this month

My family used 50 kilowatt hours of electricity last month, and the electricity charge was 30 yuan. This month, we used 70 kilowatt hours, and the electricity charge should be 42 yuan. Write out the quantitative relationship

1 kwh = 1 kwh, 30 / 50 = 0.6 yuan / kWh
70 * 0.6 = 42 yuan

Xiaoming's household electricity is 80 kwh, Xiaohong's 60 kWh and Xiaohua's 100 kwh. Xiaoming, Xiaohua and Xiaohong pay 120 yuan in total
How much should each family pay according to their electricity consumption

Hello
Xiaoming family payment: 120 × 80 / (80 + 60 + 100) = 40 (yuan)
Xiaohongjiafu: 120 × 60 / (80 + 60 + 100) = 30 (yuan)
Xiaohua Jiafu: 120 × 100 / (80 + 60 + 100) = 50 (yuan)

My family used 85 kwh of electricity last month, and the electricity charge was 47.6 yuan. My family used 50 kwh last month, how much is the electricity charge? Proportional solution Is it a positive ratio or a housing ratio