ThmDex – An index of mathematical definitions, results, and conjectures.
Formulation F11180 on D4861: Student's random real number
F11180
Formulation 1
Let $X_1, \, \ldots, \, X_N \in \text{Gaussian}(\mu, \sigma)$ each be a D210: Gaussian random real number such that
(i) \begin{equation} N \in \{ 2, 3, 4, \, \ldots \} \end{equation}
(ii) $X_1, \, \ldots, \, X_N$ is an D2713: Independent random collection
(iii) \begin{equation} \overline{X} : = \frac{1}{N} \sum_{n = 1}^N X_n \end{equation}
(iv) \begin{equation} S : = \left( \frac{1}{N - 1} \sum_{n = 1}^N (X_n - \overline{X}_N)^2 \right)^{1 / 2} \end{equation}
A D3161: Random real number $T \in \text{Random}(\mathbb{R})$ is a student's random real number with parameter $(N - 1, \mu, \sigma)$ if and only if \begin{equation} T \overset{d}{=} \frac{\overline{X} - \mu}{S / \sqrt{N}} \end{equation}