Issue 26977, remove unneeded line in pvariance (duplicate call to _ss).
diff --git a/Lib/statistics.py b/Lib/statistics.py
index af5d41e..fc0c3d2 100644
--- a/Lib/statistics.py
+++ b/Lib/statistics.py
@@ -593,7 +593,6 @@
     n = len(data)
     if n < 1:
         raise StatisticsError('pvariance requires at least one data point')
-    ss = _ss(data, mu)
     T, ss = _ss(data, mu)
     return _convert(ss/n, T)