The classical Jensen inequality and its reverse are discussed by means of internally dividing points. J.I. Fujii pointed out that the concavity is also expressed by externally dividing points. In this paper, we shall discuss an external version of the arithmetic-geometric mean inequality: For positive real numbers $x_i, y_i \geq 0$ for $i=1,2,\cdots, n$ and $r\geq 0$
\begin{align*}
(1+r)\cdot \frac{x_1+x_2+\cdots +x_n}{n} & - r\cdot \frac{y_1+y_2+\cdots +y_n}{n} \\
& \leq \left( \frac{x_1+x_2+\cdots +x_n}{n} \right)^{1+r} (\sqrt[n]{y_1y_2\cdots y_n})^{-r}.
\end{align*}