When a compressor pumps one CFM (cubic foot per minute), that means the intake port inhales one cubic foot of free air (air at atmospheric pressure, which is 0 psig) per minute. (Note: A CFM does not mean in any sense the compressed volume.) So the unit really measures the mass of air flowing per minute, not volume per minute, since a cubic foot of free air is a unit of mass.
This second scale has a mean and standard deviation that have been arbitrarily set. A z score, for example, is a raw score that has been transformed to a scale with a mean of 0 and a standard deviation of 1.
z-Scores and Location (cont.) â¢The process of changing an X value into a z-score involves creating a signed number, called a z-score, such thata. The sign of the z-score (+ or â) identifies whether the X value is located above the mean (positive) or below the mean (negative).