<span>The null hypothesis states that a population parameter is equal to a value. The null hypothesis is often an initial claim that researchers specify using previous research or knowledge. ... The alternative hypothesis is what you might believe to be true or hope to prove true.</span>
The formule is about area of a circle.

We need to solve the equation for x. Where x is the radius of the circle.
In order to solve it for x, we need isolate it for x on left side.
So, first we need to get rid pi from left side.
On dividing both sides by pi, we get


Taking square root on both sides, we get


Find A first by using formula: (a+b)/2= midpoint
so: A = [(-17)+(55)]/2
= 36
Now find B using midpoint formula:
B: (a+b)/2
=36+0/2
=18