The density of the Earth, at any distance r from its center, is approximately p = [14.2

Question:

The density of the Earth, at any distance r from its center, is approximately p = [14.2 ─ 11.6(r/R)] X 103 kg/m3 Where R is the radius of the Earth, Show that this density leads to a moment of inertia I = 0.330MR2 about an axis through the center, where M is the mass of the Earth.