the official size of a NCAA basketball has a circumference of almost 31.4 inches. find the amount of cubic inches of air that the basketball can hold.
C = 2πr = 31.4
Solve for r in terms of π.
V = (4πr^3)/3
Insert values to find volume (V).
Of course, there will be some small error, because you are not subtracting the thickness of the ball material.