[methods] E(X), Var(X) and sd(X) for bin. dists

diff --git a/methods/statistics.tex b/methods/statistics.tex
index d776b4adce381dd8aa5b70fe7d74dba242f3cca8..4c398f00c4d32db31f36dba0a9432d3317a354d6 100644 (file)
--- a/methods/statistics.tex
+++ b/methods/statistics.tex
@@ -154,4 +154,16 @@
 
   \[ \Pr(X \ge a) = 1 - \Pr(X < a) \]
 
+  \subsection{Expected value of a binomial distribution}
+
+  \[ E(X \sim \operatorname{Bi}(n,p))=np \]
+
+  \subsection{Variance}
+
+  \[ \sigma^2(X) = np(1-p) \]
+
+  \subsection{Standard deviation}
+
+  \[ \sigma(X) = \sqrt{np(1-p)} \]
+
 \end{document}