
harmonic mean


The harmonic mean (h) of a set of given numbers a_{1}, a_{2}, a_{3}, . . ., a_{n} is defined as the reciprocal of the arithmetic mean of 1/a_{1}, 1/a_{2}, 1/a_{3}, . . ., 1/a_{n}, that is,
h = n / (1/a_{1} + 1/a_{2} + 1/a_{3} + . . . + 1/a_{n})

