Let $x_1, \ldots, x_N \in [0, \infty)$ each be a D993: Real number such that
(i) | $a \in \mathbb{R}$ is a D2455: Real geometric mean of $x_1, \ldots, x_N$ |
Then
\begin{equation}
a
=
(x_1 x_2 \cdots x_N)^{1 / N}
\end{equation}