The equation for the Volume of a Sphere is:
V =
πr²
You have been given the radius of 4.5 cm, so all you have to do is plug this information into the equation and solve!
V =
π(4.5)²
↓
V =
π × 20.25 or V=
× 20.25π
↓
V= 27π (plug this into your calculator to get your numerical value)
V≈ 84.82