Light in a vacuum is incident on a transparent glass slab. Theangle of incidence is 35.6°. The slab is then immersed in apool of liquid. When the angle of incidence for the light strikingthe slab is 12.5°, the angle of refraction for the lightentering the slab is the same as when the slab was in a vacuum. What is the index of refraction of the liquid?