harmonic mean

https://doi.org/10.1351/goldbook.H02745
The number of observations, divided by the sum of reciprocals of the observations. Symbol: x ̄ h. It can be calculated with the formula: \[\bar{x}_{\text{h}} = \frac{n}{\sum x_{j}^{-1}}\]
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 @R05179@ 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 (https://doi.org/10.1351/pac199466030595)