Answer:
4.5 meters
Explanation:
At the beginning of our observations, the girl is found 1 meter below sea level. Sea level refers to an average level of the surface of a body of water from which heights may be measured. In this case, the girl starts with 1 meter below sea level. However, she then dives another 3.5 meters. This movement occurs in the same direction (deeper). The girl, therefore, is now at 4.5 meters.