you find the answer by gathering the total number of students not supportive over the total number of students. in this case it would be . then, you simplify it so that its a number over 100, so it would be . Then, you just convert that to a percentage, 76%
I take it you mean the average gallons lost an hour, in which case you would do 58,432.4 - 56,475.2 to get 1,597.2 to which you divide by 2 getting your final answer of 978.6