diff -r 21076e24cd8a Lib/statistics.py
--- a/Lib/statistics.py Sat Sep 19 13:39:03 2015 +0200
+++ b/Lib/statistics.py Sat Sep 19 21:52:32 2015 +0300
@@ -290,7 +290,8 @@
     n = len(data)
     if n < 1:
         raise StatisticsError('mean requires at least one data point')
-    return _sum(data)/n
+    # Circumvents OverflowErrors at the cost of precision and time.
+    return _sum([num/n for num in data])
 
 
 # FIXME: investigate ways to calculate medians without sorting? Quickselect?