Answer: He cannot see a ship that is 4.5 miles away.
Explanation:
Since we have given that
![d=3√(h)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/gwer6gwyymrj7d6dvn7xqmclmvr7jdl1q1.png)
Here, h is the eye level above the water
d is the distance away.
If h = 12 feet
We will get :
![d=3√(12)\\\\d=3* 2√(3)\\\\d=6√(3)\\\\d=10.39](https://img.qammunity.org/2021/formulas/mathematics/middle-school/vbw4lmx4oknjkyg548ky3wsnu6r3luoi7q.png)
Hence, it is 10.39 feet away when eye level is 12 feet above the water.
Therefore , he cannot see a ship that is 4.5 miles away.