Find the volume of a sphere with a surface area of 36π in^2 (type an exact answer in terms of π.)

In order to have any chance of answering this question,
you need to know the formulas for the area and volume
of a sphere.
In fact, I'll let you in on a secret: That's the whole purpose of
this question ! Nobody actually needs to know the volume of
this sphere ! And if they did, they wouldn't ask high-school
students who are just learning this stuff. The REASON for this
question is to help you find out whether you know the formulas
for the area and volume of a sphere, and give you a chance to
go back and review them if you don't remember them.

Here they are, for your edification:

==> Area of a sphere = 4 π (radius)²

==> Volume of a sphere = (4/3) π (radius)³

That's everything you need in order to answer the question.
Here's how to use them:

-- The area of the sphere is 36π in²

Area of a sphere = 4 π (radius)²

36 π in² = 4 π (radius)²

Divide each side by 4π :
9 in² = (radius)² ,
so
==> radius = 3 inches.

Take that information, and use it in the volume formula:

Volume of a sphere = (4/3) π (radius)³

Volume = (4/3) π (3 in)³

Volume = (4/3) π (27 in³)

==> Volume = 36 π in³

X=3 and y=4 is the answer