7.8 is what percent of 39.4 - 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 39.4 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 39.4, so we can write it down as 100%=39.4.
4. We know, that x% equals 7.8 of the output value, so we can write it down as x%=7.8.
5. Now we have two simple equations:
1) 100%=39.4
2) x%=7.8
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:
100%/x%=39.4/7.8
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 7.8 is what percent of 39.4

100%/x%=39.4/7.8
(100/x)*x=(39.4/7.8)*x       - we multiply both sides of the equation by x
100=5.0512820512821*x       - we divide both sides of the equation by (5.0512820512821) to get x
100/5.0512820512821=x
19.796954314721=x
x=19.796954314721

now we have:
7.8 is 19.796954314721% of 39.4