I honestly dnt get this ! we didn't do it last year and my teacher didnt explain it?

An aquarium is 36 inches long, 24 inches wide and 16 inches tall. The aquarium is filled with distilled water to a level of 12 inches. If a cubic foot of distilled water weighs 62.4 pounds, how many pounds of water are in the aquarium? express your answer as a decimal correct to the tenths place.