What is 0.0004 percent of 7.9 - 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 7.9 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 7.9 is 100%, so we can write it down as 7.9=100%.
4. We know, that x is 0.0004% of the output value, so we can write it down as x=0.0004%.
5. Now we have two simple equations:
1) 7.9=100%
2) x=0.0004%
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:
7.9/x=100%/0.0004%
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 0.0004% of 7.9

7.9/x=100/0.0004
(7.9/x)*x=(100/0.0004)*x       - we multiply both sides of the equation by x
7.9=250000*x       - we divide both sides of the equation by (250000) to get x
7.9/250000=x
3.16E-5=x
x=3.16E-5

now we have:
0.0004% of 7.9=3.16E-5