mean The harmonic mean is an average which is useful for sets of numbers which are defined in relation to some unit , for example speed (distance per unit of time). = \frac{n}{\sum_{i=1}^n \frac{1}{x_i}}" src="http://upload.wikimedia.org/math/8/8/8/888d8ebf1d38de9e22090357b9bc1e07.png"> [ edit ] An example An experiment yields the following data: 34,27,45,55,22,34 To get the harmonic