What is 7.5 percent of 643.69 - 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 643.69 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 643.69 is 100%, so we can write it down as 643.69=100%.
4. We know, that x is 7.5% of the output value, so we can write it down as x=7.5%.
5. Now we have two simple equations:
1) 643.69=100%
2) x=7.5%
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:
643.69/x=100%/7.5%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 7.5% of 643.69

643.69/x=100/7.5
(643.69/x)*x=(100/7.5)*x       - we multiply both sides of the equation by x
643.69=13.333333333333*x       - we divide both sides of the equation by (13.333333333333) to get x
643.69/13.333333333333=x
48.27675=x
x=48.27675

now we have:
7.5% of 643.69=48.27675