Avoid double rounding in test code

Author: rhettinger

Lib/test/test_statistics.py

@@ -2237,7 +2237,9 @@ def test_decimal_sqrt_of_frac(self):
             # Confirm expected root with a quad precision decimal computation
             with decimal.localcontext(decimal.DefaultContext) as ctx:
                 ctx.prec *= 4
-                high_prec_root = (Decimal(numerator) / Decimal(denominator)).sqrt()
+                high_prec_ratio = Decimal(numerator) / Decimal(denominator)
+                ctx.rounding = decimal.ROUND_05UP
+                high_prec_root = high_prec_ratio.sqrt()
             with decimal.localcontext(decimal.DefaultContext):
                 target_root = +high_prec_root
             self.assertEqual(root, target_root)