To find the depth of the ocean, we need to use the formula:depth = (speed of sound * time) / 2
where time is the time elapsed from when the echo was sent until it was picked up. In this case, the time elapsed is 3 seconds. So, the depth of the ocean is:
depth = (1540 m/s * 3s) / 2
depth = 2310 mSo, the depth of the ocean at that point is 2310 meters.