Question 40807
First, note that it is clear that the ball will be completely submerged.  If this were not so, we would have to be more careful.  Since it IS so, the ball simply pushes up an equal volume of water, so we can add the volume of the ball to the volume of the water as though it were all water.

{{{Vol[C]=A[b]h =(pi *r^2)*h}}} and {{{Vol[S]=(4/3)* pi *r^3}}}
Using these, the ball has volume {{{421(cm^3)}}} and the volume of the water in the can is {{{3359(cm^3)}}} for a total of {{{3780(cm^3)}}}.  Setting {{{(pi *9^2)*h=3780}}} and solving for h yields {{{h=3780/(81pi) = 14.85*cm}}}.
(Answers will vary slightly depending on whether you use your calculator's version of {{{pi}}} or type in 3.14.)