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?
a.
44.5%
b.
97.8%
c.
55.4%
d.
67.5%

Ahigh-altitude spherical weather balloon expands as it rises, due to the drop in atmospheric pressure. suppose that the radius r increases at the rate of 0.02 inches per second, and that r = 36 inches at time t = 0. determine the equation that models the volume v of the balloon at time t, and find the volume when t = 360 seconds. v(t) = 4π(0.02t)2; 651.44 in3 v(t) = 4π(36 + 0.02t)2; 1,694,397.14 in3 v(t) = four pi times the product of zero point zero two and t to the third power divided by three.; 4,690.37 in3 v(t) = four pi times the quantity of thirty six plus zero point zero two t to the third power divided by three.; 337,706.83 in3