At the surface of the ocean, the water pressure is the same as the air pressure above the water, about 15 \quad lb/in^2, Below the surface the water pressure increases by about 4.44 \quad lb/in^2 for every 10 ft of descent.
Write a function f(x) which expresses the water pressure in pounds per square inch as a function of the depth in inches below the ocean surface.
At what depth is the pressure 100 \quad lb/in^2? Include the units in your answer

Question

At the surface of the ocean, the water pressure is the same as the air pressure above the water, about 15 \quad lb/in^2, Below the surface the water pressure increases by about 4.44 \quad lb/in^2 for every 10 ft of descent.
Write a function f(x) which expresses the water pressure in pounds per square inch as a function of the depth in inches below the ocean surface. 
At what depth is the pressure 100 \quad lb/in^2? Include the units in your answer