The basic formula used to calculate the volume of a sphere is:

The variables

The formula can be used only if the radius of the sphere is known. We are given the measure of the diameter of the sphere as a means to find its radius. Since the diameter is 5 inches, divide it by 2 to get the radius.

We will now substitute all the known values in the formula for volume. Take the value of π to be

We have thus calculated the volume of the sphere using the diameter as about