Determining which compressor must be bought by the diver for the given condition.
A diver is planning to salvage a Spanish galleon located in 200 feet of water. He plans to use a diving suit that will be supplied with air from a hose (suppose this to be amply sized) connected to a compressor that he will locate in his boat on surface. When he goes to the dive shop to purchase an appropriate compressor he finds that there are three compressors that will deliver the air he needs but they are rated for 75, 125, and 200 psig. The compressors with the higher pressure ratings have higher costs. Which compressor should he buy and why?