Charges $Q, 2 Q$ and $4 Q$ are uniformly distributed in three dielectric solid spheres 1,2 and 3 of radii $R / 2, R$ and $2 R$ respectively, as shown in figure. If magnitudes of the electric fields at point $P$ at a distance $R$ from the centre of spheres 1,2 and 3 are $E_1 E_2$ and $E_3$ respectively, then