87.7 is what percent of 399.4 - 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 399.4 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 399.4, so we can write it down as 100%=399.4.
4. We know, that x% equals 87.7 of the output value, so we can write it down as x%=87.7.
5. Now we have two simple equations:
1) 100%=399.4
2) x%=87.7
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%=399.4/87.7
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 87.7 is what percent of 399.4

100%/x%=399.4/87.7
(100/x)*x=(399.4/87.7)*x       - we multiply both sides of the equation by x
100=4.5541619156214*x       - we divide both sides of the equation by (4.5541619156214) to get x
100/4.5541619156214=x
21.957936905358=x
x=21.957936905358

now we have:
87.7 is 21.957936905358% of 399.4