Answer:
the beetle's actual distance beneath the surface, d = 3.2 cm
Explanation:
The refractive index for the plastic is about 1.60
For overhead viewing, the expression for refractive index is
n = actual depth / apparent depth
Rearrange for actual depth
actual depth d = n x apparent depth
d = 1.60 x 2.0 cm
d = 3.2 cm