Finding the mean orbital radius of the proton's wavefunction.

So I think I know how to do part A. Assuming that the given .527 angstroms is the distance from the center of mass to the electron I can find the distance from the center of mass to the proton. My center of mass then comes out to be inside the proton. I think that it the right answer but I am not sure. I have no clue how to do parts B and C though. If someone could do this problem I would be very grateful.