Attractive nuisances can create liability risks. Learn what a home attractive nuisance is and see the most common attractive nuisance examples.
In mathematics, the harmonic mean (sometimes called the subcontrary mean) is one of several kinds of average, and in particular one of the Pythagorean means. Typically, it is appropriate for situations when the average of rates is desired. The harmonic mean can be expressed as the reciprocal of the arithmetic mean of the reciprocals. As a simple example, the harmonic mean of 1, 2, and 4 is 3 1 1 + 1 2 + 1 4 = 1 1 3 ( 1 1 + 1 2 + 1 4 ) = 12 7 .
The harmonic mean is the special case of the power mean and is one of the Pythagorean means. In older literature, it is sometimes called the subcontrary mean. The volume-to-surface area ratio for a cylindrical container with height and radius and the mean curvature of a general surface are related to the harmonic mean.