When leaving a fish tank, a ray moving at 31.0 degrees in glass (n = 1.50) exits into the air. At what angle does it enter the air?
(Unit=deg)

answer: good job it's all correct !

explanation:

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west