volume of a ball = 4/3 x pi x r^3
volume = 4186.67
4186.67 = 4/3 x pi x r^3
1st step multiply PI x 4/3 ( 4/3 x 3.14 = 4.18667)
now you have 4186.67 = 4.18667 x r^3
2nd step divide both sides by 4.18667 to get r^3
r^3 = 4186.67 / 4.18667
r^3 = 1000
solve for r by finding cubic root of 1000
r = ∛1000
r = 10
diameter = 2r = 2(10) = 20 cm
