I need some help finding the volume of a sphere with a diameter of 18.6cm. The website says the answer I got from my calculator was wrong! Help would be greatly appreciated!

Answer:
V = 3,367.6 cm³
Step-by-step explanation:
Diameter of sphere (D) = 18.6 cm
radius (r) = ½(18.6) = 9.3
π = 3.14
Formula for volume of a sphere = ⁴/3πr³
Plug in the values
V = ⁴/3 × 3.14 × 9.3³
V = ⁴/3 × 3.14 × 804.357
V = (4*3.14*804.357)/3
V = 3,367.57463
V = 3,367.6 cm³ (nearest tenth)