We are asked to determine the speed of light in a medium with an index of refraction of 1.95. To do that we will use the following formula:
[tex]v=\frac{c}{n}[/tex]Where:
[tex]\begin{gathered} v=\text{ speed of light in the medium} \\ c=\text{ speed of light in vacuum} \\ n=\text{ index of refraction} \end{gathered}[/tex]Now, we substitute the values:
[tex]v=\frac{3\times10^8\text{ m/s}}{1.95}[/tex]Solving the operations:
[tex]v=1.54\times10^8\text{ m/s}[/tex]