Question

Ronnie wants to lower his utility bills to save money on his monthly expenses. He discovers that if he replaces his water heater with a solar water heater his monthly utility bills can decrease around 50% to 85%. At the end of the year Ronnie wants to calculate the percentage his new solar water heater saved him in the utility bills compared to last year. Ronnie's total utility expenses for this year are $862.40 and last year the utility expenses were $1935.67. What percentage did Ronnie save on his utlility bills by switching to a solar water heater?

Answer 1

First find the dollar savings:
1935.67 − 862.40 = 1073.27

Then compute the percent saved:
(1073.27 ÷ 1935.67) × 100% ≈ 55.45%

Ronnie saved $1,073.27, which is about 55.45% of last year’s utility bills.