Two electric dipoles of dipole moments $1.2 \times 10^{-30} \mathrm{~cm}$ and $2.4 \times 10^{-30} \mathrm{~cm}$ are placed in two difference uniform electric fields of strengths $5 \times 10^4 \mathrm{NC}^{-1}$ and $15 \times 10^4 \mathrm{NC}^{-1}$ respectively. The ratio of maximum torque experienced by the electric dipoles will be $\frac{1}{x}$. The value of $x$ is $\_\_\_\_$ .