Correct the heading levels (GH-12338)



diff --git a/Doc/library/statistics.rst b/Doc/library/statistics.rst
index 97e1c3a..b5521b7 100644
--- a/Doc/library/statistics.rst
+++ b/Doc/library/statistics.rst
@@ -491,7 +491,7 @@
 
 
 :class:`NormalDist` objects
-===========================
+---------------------------
 
 :class:`NormalDist` is a tool for creating and manipulating normal
 distributions of a `random variable
@@ -611,7 +611,7 @@
 
 
 :class:`NormalDist` Examples and Recipes
-----------------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 :class:`NormalDist` readily solves classic probability problems.