The index of refraction is given by:
[tex]n=\frac{c}{v}[/tex]where c is the speed of light and v is the velocity of light on the medium. We know that the speed of light is 3e8 m/s and that the velocity of light in the medium is 1.75e8 m/s then we have:
[tex]\begin{gathered} n=\frac{3\times10^8}{1.75\times10^8} \\ n=1.71 \end{gathered}[/tex]Therefore, the index of refraction is 1.71
