What is 87.8 percent of 5.15 - 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 5.15 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 5.15 is 100%, so we can write it down as 5.15=100%.
4. We know, that x is 87.8% of the output value, so we can write it down as x=87.8%.
5. Now we have two simple equations:
1) 5.15=100%
2) x=87.8%
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:
5.15/x=100%/87.8%
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 87.8% of 5.15

5.15/x=100/87.8
(5.15/x)*x=(100/87.8)*x       - we multiply both sides of the equation by x
5.15=1.1389521640091*x       - we divide both sides of the equation by (1.1389521640091) to get x
5.15/1.1389521640091=x
4.5217=x
x=4.5217

now we have:
87.8% of 5.15=4.5217