In the refraction portion of today's lab you did not account for the refraction due to the glass between the water and your eye. Assuming the glass...

In the refraction portion of today’s lab you did not account for the refraction due to the glass between the water and your eye. Assuming the glass is 4mm thick and is crown glass (nglass=1.52), what is the size of the systematic error you should have noticed? (Consider starting by drawing a picture showing a ray passing from air into glass and then into water and comparing that with a second drawing without the water)