AM ⁡ ( x 1 , … , x n ) = 1 n ( x 1 + ⋯ + x n ) GM ⁡ ( x 1 , … , x n ) = | x 1 × ⋯ × x n | n HM ⁡ ( x 1 , … , x n ) = n 1 x 1 + ⋯ + 1 x n {\displaystyle {\begin{aligned}\operatorname {AM} \left(x_{1},\;\ldots ,\;x_{n}\right)&={\frac {1}{n}}\left(x_{1}+\;\cdots \;+x_{n}\right)\\[9pt]\operatorname {GM} \left(x_{1},\;\ldots ,\;x_{n}\right)&={\sqrt[{n}]{\left\vert x_{1}\times \,\cdots \,\times x_{n}\right\vert }}\\[9pt]\operatorname {HM} \left(x_{1},\;\ldots ,\;x_{n}\right)&={\frac {n}{\displaystyle {\frac {1}{x_{1}}}+\;\cdots \;+{\frac {1}{x_{n}}}}}\end{aligned}}}