Why is geometric mean used for averaging bacterial concentrations?

The use of geometric mean for averaging bacterial concentrations is particularly beneficial because it dampens the effect of extreme values. When dealing with microbial counts, data can often display significant variability, with some samples showing extremely high concentrations of bacteria. This variability can skew the results when using arithmetic means, which may not accurately represent typical conditions in a given dataset.

The geometric mean, on the other hand, calculates the central tendency of a set of numbers by taking the product of the values and then applying the nth root (where n is the number of values). This method inherently reduces the influence of outliers, providing a more accurate representation of the typical concentration levels in microbial studies. This characteristic makes the geometric mean especially useful in environmental science and public health contexts, where understanding true average conditions is critical for decision-making and regulatory compliance.