1. A particular fish tank filled with fresh water (n = 1.33) has a coral reef sticker stuck to the exterior wall outside the fish tank. The tank's walls are 2 cm thick, but a goldfish inside the tank sees the sticker 0.6 cm away from the water-wall interface. What is the index of refraction of the tank's walls? s' = (n2/n1) * (s) Plugged in the values into the aforementioned equation and got an index of refraction of either 0.339 or 4.43, depending on which index is in the numerator and which is in the denominator (and vice versa).