Moyenne arithmétique:

Variable dicrete

\begin{eqnarray} {\displaystyle A={\frac {1}{n}}\sum _{i=1}^{n}x_{i}={\frac {x_{1}+x_{2}+\cdots +x_{n}}{n}}} \end{eqnarray}

\begin{eqnarray} {\displaystyle A={\frac {1}{N}}\sum _{i=1}^{K}n_{i} \times x_{i}={\frac {n_{1} \times x_{1}+n_{2} \times x_{2}+\cdots +n_{K} \times x_{K}}{N}}} \end{eqnarray}

Exemple:

\begin{eqnarray} {\displaystyle A={\frac {281}{50}} = 5.62} \end{eqnarray}

Variable classée:

\begin{eqnarray} {\displaystyle A={\frac {1}{N}}\sum _{i=1}^{K}n_{i} \times c_{i}={\frac {n_{1} \times c_{1}+n_{2} \times c_{2}+\cdots +n_{K} \times c_{K}}{N}}} \end{eqnarray}

Exemple:

\begin{eqnarray} {\displaystyle A={\frac {8497.5}{50}} = 169.95} \end{eqnarray}

Moyenne géométrique:

\begin{eqnarray} { \displaystyle G. M = (x_{1} \times x_{2} \times …x_{n})^{^{\frac{1}{n}}} } \end{eqnarray}