643.66 is what percent of 800 - 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 800 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 800, so we can write it down as 100%=800.
4. We know, that x% equals 643.66 of the output value, so we can write it down as x%=643.66.
5. Now we have two simple equations:
1) 100%=800
2) x%=643.66
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%=800/643.66
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 643.66 is what percent of 800

100%/x%=800/643.66
(100/x)*x=(800/643.66)*x       - we multiply both sides of the equation by x
100=1.2428922101731*x       - we divide both sides of the equation by (1.2428922101731) to get x
100/1.2428922101731=x
80.4575=x
x=80.4575

now we have:
643.66 is 80.4575% of 800