Explanation:

Given,
The radius of a cylindrical tube (r) =12 cm
Level of water raised in the tube (h) = 6.75 cm
Volume of the cylinder = ∏×r²×h
= ∏×12²×6.75
Let r be the radius of the spherical ball
Volume of the sphere = (4/3)∏×r³ …………………………(ii)
To find the radius of the spherical ball of unknown radius r we need to equate equations i and ii
We get,
∏×12²×6.75= 12.571 r³
r³ = 729
r = 9 cm
The radius of the spherical ball is 9 cm.