First, you would need to create an equation for this problem.

=

Next, you would cross multiply.
5x = 8,000
Now, all you would have to do is isolate the x. To do this, you would divide both sides by 5.
x = <span>
1,6001,600 people are considered middle class. I hope this helps!</span>
Answer:
25π
Step-by-step explanation:
1) for whole circuit: A=π*r², where r - radius of the given circle;
2) for a quater of the circuit: A=πr²/4;
3) finally, A=π*100/4=25π.
- 10, you go down 4 - this is shown because to get from two to 10 in two, you have to go 2+4=6+4=10