In mathematics, a function f of n variables x1, ..., xn leads to a Chisini mean M if for every vector <x1, ..., xn>, there exists a unique M such that f(M,M, ..., M) = f(x1,x2, ..., xn). The arithmetic, harmonic, geometric, generalised, Heronian and quadratic means are all Chisini means, as are their weighted variants. They were introduced by Oscar Chisini in 1929. See also Fréchet mean Generalized mean Jensen's inequality Quasi-arithmetic mean Stolarsky mean References Mathematical analysis Means