A student is trying to calculate the density of a ball. She already knows the mass, but she needs to determine the volume as well. Which of the following formulas can be used to calculate the volume of the ball?

First, the student needs to get the radius of the ball. He/she can do that by simply measuring the diameter and dividing it by two to get the radius.

The next step would be to calculate the volume of the ball using the rule of volume of a perfect sphere (since the ball is considered a perfect sphere). The rule for calculating the volume of sphere is as follows:

volume of sphere = (4/3) x pi x (radius) ^3 ... > this is the correct formula

The next step is to calculate the density, since the mass of the ball is known and the volume is calculated in the previous step, therefore, the density of the ball can be calculated using the following rule:

density = mass / volume