ピタゴラス平均
a < b ⇒ M  ( a , x 1 , x 2 , ... x n ) < M  ( b , x 1 , x 2 , ... x n ) {\displaystyle a<b\Rightarrow \operatorname {M} (a,x_{1},x_{2},\ldots x_{n})<\operatorname {M} (b,x_{1},x_{2},\ldots x_{n})}