An infinite grounded conducting plane is positioned along the xz plane. A point charge +2q is positioned at coordinates (x,y,z)=(3a,4a,0) while a second point charge -q is positioned at coordinates (0,a,0). Find the surface charge density on the surface of the conducting plane at the origin. Simplify your answer to the form σ = N(q)/(d^2), where N is a number.