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z-Score

The $z$-score associated with the $i$th observation of a random variable $x$ is given by

\begin{displaymath}
z_i\equiv {x_i-\bar x\over \sigma},
\end{displaymath}

where $\bar x$ is the Mean and $\sigma$ the Standard Deviation of all observations $x_1$, ..., $x_n$.




© 1996-9 Eric W. Weisstein
1999-05-26