A scuba diver uses an empty vertical tube, closed at the top and open at the bottom, to measure her depth below sea level when diving in the ocean. The tube is 7.20 cm long. She dives below the surface until the water has risen into the tube a distance of 2.31 cm from the open end of the tube. Assuming the temperature of the air in the tube stays constant during the dive, what is the diver's depth at this point? The average density of sea water is 1,030 kg/m3.