The angle of incidence \(\theta_{1}=25^{\circ}\)

The angle of refraction \(\theta_{2}=20,6^{\circ}\)

\(n_{1}=1,333\)

We need to calculate the refractive index for the unknown medium.

We can use Snell's law to calculate the unknown refractive index, \(n_{2}\)

According to Snell's Law:

\[

\begin{aligned}

n_{1} \sin \theta_{1} &=n_{2} \sin \theta_{2} \\

n_{2} &=\frac{n_{1} \sin \theta_{1}}{\sin \theta_{2}} \\

n_{2} &=\frac{1,333 \sin 25^{\circ}}{\sin 20,6^{\circ}} \\

n_{2} &=1,6

\end{aligned}

\]

Typically glass has a refractive index between 1,5 to 1,9 . Therefore the unknown medium is typical glass.