Density Questions

Average density of the earth:

A jar is filled with two non-mixing liquids $1$ and $2$ having densities ${\rho }_1$ and ${\rho }_2$ respectively. A solid ball of density ${\rho }_3$ is dropped and comes to equilibrium such that it floats at the interface, partially in both liquids. Which of the following is true for ${\rho }_1$, ${\rho }_2$ and ${\rho }_3$?