642.68 is what percent of 810 - 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 810 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 810, so we can write it down as 100%=810.
4. We know, that x% equals 642.68 of the output value, so we can write it down as x%=642.68.
5. Now we have two simple equations:
1) 100%=810
2) x%=642.68
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%=810/642.68
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 642.68 is what percent of 810

100%/x%=810/642.68
(100/x)*x=(810/642.68)*x       - we multiply both sides of the equation by x
100=1.2603472956993*x       - we divide both sides of the equation by (1.2603472956993) to get x
100/1.2603472956993=x
79.343209876543=x
x=79.343209876543

now we have:
642.68 is 79.343209876543% of 810