HALP!!!! I have a problem. A problem that goes like this:A steel ball-bearing with a circumference of 32.5 mm weighs 4.20 g. What is the density of the steel in g/cm3 (V of a sphere = 4/3 πr3; circumference of a circle = 2πr)?

I keep trying it and I get 7.245g/cm3 (that is grams per centimeter cubed). I need help. Plz. Your math expertise is in dire need.