Spherical Shell - Variable Mass Density

A hollow spherical shell of radius $1$ has its center at the origin of the $xyz$ coordinate system. The shell's variable area mass density is expressed as $z^2$ .

A test mass is positioned at $(x,y,z) = (0,0,2)$ . For simplicity, assume that the universal gravitational constant and test mass are both numerically equal to $1$ .

What is the magnitude of the gravitational force exerted by the shell on the test mass?