40; base it off of the y-intercept [C]. What is the unit of measurement?
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>
I found two using a little C# program:
9,10,11,12,13,14,15,16
and
18,19,20,21,22
(if you're interested in the program drop me a msg)
The vertex is ( 2,4)
The axis of symmetry is 2 .
Direction of parabola ( i don’t know sorry )