For this case, what we must do is multiply the depth of the fish by the fraction of depth of the turtle. We have then: (-3/4) * (1/3) = (- 3 * 1) / (4 * 3) = - 1/4 mile Therefore, the depth of the turtle on the surface of the water is: -1/4 mile Answer: the turtle's depth is: -1/4 mile