(3√5)2 i got 45 bit my calculator says 15. ?

What is the value of x in the diagram below?

Ineed to know the answer to this algebra question.

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8