Answer
$n_1 \lt n_2$
Work Step by Step
We can write Snell's Law:
$n_1~sin~\theta_1 = n_2~sin~\theta_2$
where $n_i$ is the refractive index and $\theta_i$ is the angle as measured from the perpendicular with the surface boundary.
If $\theta_i$ is larger, then $n_i$ must be smaller in order for the equality to hold.
Since $\theta_1 \gt \theta_2$, then $~~n_1 \lt n_2$
