posted by Isabel .
A 57.0 cheerleader uses an oil-filled hydraulic lift to hold four 110 football players at a height of 1.40 . If her piston is 19.0 in diameter, what is the diameter of the football players' piston? The density of the oil in the hydraulic system is 900 kg/m^3.
Not having any units given, I can't go farther. Solve for d