harmonic mean

The number of observations, divided by the sum of reciprocals of the observations. Symbol: x ̄ h. It can be calculated with the formula:
x ̄ h = n ∑ x j −1
Note:
As in the case of the geometric mean, this quantity is sometimes directly (but inappropriately) calculated, for example, when evaluating kinetic analytical results where the reaction time is inversely proportional to concentration.
Source:
PAC, 1994, 66, 595 (Nomenclature for the presentation of results of chemical analysis (IUPAC Recommendations 1994)) on page 602