Clark bought a fish tank that is 4 ft long 2 ft wide by 1.5 ft high. He filled the tank with water 1 feet deep. He then added the 6 fish he had purchased to the tank and the water level rose to 1.2 feet. What is the approximate volume of the largest fish if the largest fish is twice as big as the next fish and so on? Round the answer to the nearest hundredth.