Answer:
1.34
Step-by-step explanation:
Snell's law tells you ...
[tex]n_i\cdot\sin{\theta_i}=n_r\cdot\sin{\theta_r}[/tex]
Solving for [tex]n_r[/tex], we get ...
[tex]n_r=n_i\cdot\dfrac{\sin{\theta_i}}{\sin{\theta_r}}=1.25\cdot\dfrac{\sin{40.1^\circ}}{\sin{36.9^\circ}}\approx 1.34[/tex]
The unknown material has an index of refraction of 1.34.