diff --git a/statistics.rst b/statistics.rst
index d757b4f..533c48a 100644
--- a/statistics.rst
+++ b/statistics.rst
@@ -3,6 +3,7 @@ Statistics For Engineers
 
 Normal distributions
 ====================
+Normal distributions are frequently used to represent random variables where distribution is not known.
 
 Percentiles, histograms, averages, mean, medians
 ================================================