9514 1404 393
Answer:
 491,400 ft¡lb
Step-by-step explanation:
The mass of the water is ...
 M = VĎ = LWHĎ = (25 ft)(15 ft)(7 ft)(62.4 lb/ftÂł) = 163,800 lb
The average depth is 3 ft, so the work required is equivalent to that required to raise this mass 3 ft.
 W = (3 ft)(163,800 lb) = 491,400 ft¡lb