Let $x_1, \dots, x_N \in \mathbb{R}$ each be a D993: Real number such that

(i)	$a \in \mathbb{R}$ is a D2454: Real arithmetic mean of $x_1, \dots, x_N$

Then \begin{equation} a = \frac{1}{N} \sum_{n = 1}^N x_n \end{equation}