Harmonic Mean - Relationship With Other Means

Relationship With Other Means

If a set of non-identical numbers is subjected to a mean-preserving spread — that is, two or more elements of the set are "spread apart" from each other while leaving the arithmetic mean unchanged — then the harmonic mean always decreases.

Let r be a non zero real number and let the rth power mean ( Mr ) of a series of real variables ( a1, a2, a3, ... ) be defined as

For r = -1, 1 and 2 we have the harmonic, the arithmetic and the quadratic means respectively. Define r = 0, -∞ and +∞ to be the geometric mean, the minimum of the variates and the maximum of the variates respectively. Then for any two real numbers s and t such that s < t we have

with equality only if all the ai are equal.

Let R be the quadratic mean (or root mean square). Then

Read more about this topic:  Harmonic Mean

Famous quotes containing the words relationship with, relationship and/or means:

    Guilty, guilty, guilty is the chant divorced parents repeat in their heads. This constant reminder remains just below our consciousness. Nevertheless, its presence clouds our judgment, inhibits our actions, and interferes in our relationship with our children. Guilt is a major roadblock to building a new life for yourself and to being an effective parent.
    Stephanie Marston (20th century)

    If one could be friendly with women, what a pleasure—the relationship so secret and private compared with relations with men. Why not write about it truthfully?
    Virginia Woolf (1882–1941)

    Having children can smooth the relationship, too. Mother and daughter are now equals. That is hard to imagine, even harder to accept, for among other things, it means realizing that your own mother felt this way, too—unsure of herself, weak in the knees, terrified about what in the world to do with you. It means accepting that she was tired, inept, sometimes stupid; that she, too, sat in the dark at 2:00 A.M. with a child shrieking across the hall and no clue to the child’s trouble.
    Anna Quindlen (20th century)