640.86 is what percent of 720 - step by step solution

To get the solution, we are looking for, we need to point out what we know.

1. We assume, that the number 720 is 100% - because it's the output value of the task.
2. We assume, that x is the value we are looking for.
3. If 100% equals 720, so we can write it down as 100%=720.
4. We know, that x% equals 640.86 of the output value, so we can write it down as x%=640.86.
5. Now we have two simple equations:
1) 100%=720
2) x%=640.86
where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:
100%/x%=720/640.86
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 640.86 is what percent of 720

100%/x%=720/640.86
(100/x)*x=(720/640.86)*x       - we multiply both sides of the equation by x
100=1.1234903098961*x       - we divide both sides of the equation by (1.1234903098961) to get x
100/1.1234903098961=x
89.008333333333=x
x=89.008333333333

now we have:
640.86 is 89.008333333333% of 720