Pythagorean means
Pythagorean means comprise:
In math, they are known as arithmetic mean (AM), geometric mean (GM), and harmonic mean (HM), respectively. However, harmonic mean is said with respect to a length of string to be divided, and collides with the more common usage of harmonic, which is said with respect to frequency. For fear of confusion, those terms are avoided and inverse-arithmetic mean is preferred instead.