4 is what percent of 8.1 - 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 8.1 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 8.1, so we can write it down as 100%=8.1.
4. We know, that x% equals 4 of the output value, so we can write it down as x%=4.
5. Now we have two simple equations:
1) 100%=8.1
2) x%=4
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%=8.1/4
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 4 is what percent of 8.1

100%/x%=8.1/4
(100/x)*x=(8.1/4)*x       - we multiply both sides of the equation by x
100=2.025*x       - we divide both sides of the equation by (2.025) to get x
100/2.025=x
49.382716049383=x
x=49.382716049383

now we have:
4 is 49.382716049383% of 8.1