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Definition D2144
Random real number standard deviation

Let $X \in \text{Random}(\mathbb{R})$ be a D3161: Random real number such that
 (i) $$\mathbb{E} |X|^2 < \infty$$
The standard deviation of $X$ is the D4767: Unsigned real number $$\text{Std} X : = \left( \mathbb{E}|X - \mathbb{E} X|^2 \right)^{1/2}$$

Let $X \in \text{Random}(\mathbb{R})$ be a D3161: Random real number such that
 (i) $$\mathbb{E} |X|^2 < \infty$$
The standard deviation of $X$ is the D4767: Unsigned real number $$\text{Std} X : = \sqrt{ \mathbb{E}|X - \mathbb{E} X|^2 }$$
Children
 ▶ Random real number standard error