87.2 is what percent of 81 - 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 81 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 81, so we can write it down as 100%=81.
4. We know, that x% equals 87.2 of the output value, so we can write it down as x%=87.2.
5. Now we have two simple equations:
1) 100%=81
2) x%=87.2
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%=81/87.2
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 87.2 is what percent of 81

100%/x%=81/87.2
(100/x)*x=(81/87.2)*x       - we multiply both sides of the equation by x
100=0.92889908256881*x       - we divide both sides of the equation by (0.92889908256881) to get x
100/0.92889908256881=x
107.65432098765=x
x=107.65432098765

now we have:
87.2 is 107.65432098765% of 81