Integration Problem for Calculus Homework

I'm having trouble with the following problem from my homework for a Calc. II course:

Quote:

The velocity

*v *of the flow of blood at a distance

*r *from the central axis of an artery of radius

*R* is,

where

*k *is the constant of proportionality. Find the average rate of flow of blood along a radius of the artery. (Use 0 and

*R* as the limits of integration.)

Any help would be really appreciated, thanks.

EDIT: I should probably clarify: I know how to use integration in order to find the average value of a function over a range. It's integrating the function that I'm stuck on.