642.1 is what percent of 25 - 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 25 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 25, so we can write it down as 100%=25.
4. We know, that x% equals 642.1 of the output value, so we can write it down as x%=642.1.
5. Now we have two simple equations:
1) 100%=25
2) x%=642.1
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%=25/642.1
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 642.1 is what percent of 25

100%/x%=25/642.1
(100/x)*x=(25/642.1)*x       - we multiply both sides of the equation by x
100=0.038934745366765*x       - we divide both sides of the equation by (0.038934745366765) to get x
100/0.038934745366765=x
2568.4=x
x=2568.4

now we have:
642.1 is 2568.4% of 25