The difference between Harmonic mean and Quadratic mean

When used as nouns, harmonic mean means a type of measure of central tendency calculated as the reciprocal of the mean of the reciprocals, ie, h = { n \over {1 \over x_1} + {1 \over x_2} + \cdots {1 \over x_n} }, whereas quadratic mean means a type of average, calculated as the square root of the mean of the squares, ie. q = \sqrt { x_1^2 + x_2^2 + ... + x_n^2 \over n }.


check bellow for the other definitions of Harmonic mean and Quadratic mean

  1. Harmonic mean as a noun (mathematics):

    A type of measure of central tendency calculated as the reciprocal of the mean of the reciprocals, ie, H = { n \over {1 \over x_1} + {1 \over x_2} + \cdots {1 \over x_n} }

    Examples:

    "If ''a''<sub>''n''</sub> and ''b''<sub>''n''</sub> denote the perimeters of inscribed and circumscribed regular ''n''-gons, respectively, along some circle then the harmonic mean and geometric mean of those two perimeters yield the perimeters of the inscribed and circumscribed regular 2''n''-gons, respectively, along that same circle. (This is Archimedes' Recurrence Formula.)"

  1. Quadratic mean as a noun (mathematics):

    A type of average, calculated as the square root of the mean of the squares, ie. Q = \sqrt { x_1^2 + x_2^2 + ... + x_n^2 \over n }.