A thin prism of angle $6°$ and refractive index for yellow light $\left(n_{\mathrm{Y}}\right)1.5$ is combined with another prism of angle $5°$ and $n_{\mathrm{Y}}=1.55$. The combination produces no dispersion. The net average deviation $\left(\delta \right)$ produced by the combination is ${\left(\frac{1}{x}\right)}^{°}$. The value of $x$ is _____ .

Hence, the correct answer is 4.