431.24 is what percent of 640 - 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 640 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 640, so we can write it down as 100%=640.
4. We know, that x% equals 431.24 of the output value, so we can write it down as x%=431.24.
5. Now we have two simple equations:
1) 100%=640
2) x%=431.24
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%=640/431.24
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 431.24 is what percent of 640

100%/x%=640/431.24
(100/x)*x=(640/431.24)*x       - we multiply both sides of the equation by x
100=1.484092384751*x       - we divide both sides of the equation by (1.484092384751) to get x
100/1.484092384751=x
67.38125=x
x=67.38125

now we have:
431.24 is 67.38125% of 640