from github to this gitea

covariance.md

@@ -0,0 +1,11 @@
+up:: [[statistiques]]
+#maths/statistiques 
+
+
+$$
+\begin{align}
+\mathrm{cov}(X, Y) &= \overline{X \cdot Y} - \overline{X} \cdot \overline{Y} \\[1em]
+&= \overline{(X-\overline{X}) \cdot (Y - \overline{Y})} \\[1em]
+&= \sum\limits_{n}\left( \frac{ \left( X_{n} - \overline{X}\right) \cdot \left( Y_{n} - \overline{Y} \right) }{n} \right) 
+\end{align}
+$$