90 is what percent of 421.3 - 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 421.3 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 421.3, so we can write it down as 100%=421.3.
4. We know, that x% equals 90 of the output value, so we can write it down as x%=90.
5. Now we have two simple equations:
1) 100%=421.3
2) x%=90
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%=421.3/90
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 90 is what percent of 421.3

100%/x%=421.3/90
(100/x)*x=(421.3/90)*x       - we multiply both sides of the equation by x
100=4.6811111111111*x       - we divide both sides of the equation by (4.6811111111111) to get x
100/4.6811111111111=x
21.362449560883=x
x=21.362449560883

now we have:
90 is 21.362449560883% of 421.3