BUG: fix #59965 skipna=True operations don't skip NaN in FloatingArrays

pandas/core/array_algos/masked_reductions.py

@@ -12,6 +12,7 @@
 
 from pandas._libs import missing as libmissing
 
+from pandas.core.missing import isna
 from pandas.core.nanops import check_below_min_count
 
 if TYPE_CHECKING:
@@ -57,6 +58,9 @@ def _reductions(
         else:
             return func(values, axis=axis, **kwargs)
     else:
+        if values.dtype == np.float64:
+            mask |= isna(values)
+
         if check_below_min_count(values.shape, mask, min_count) and (
             axis is None or values.ndim == 1
         ):

pandas/tests/series/test_reductions.py

@@ -6,7 +6,10 @@
 from pandas.compat import HAS_PYARROW
 
 import pandas as pd
-from pandas import Series
+from pandas import (
+    Series,
+    notna,
+)
 import pandas._testing as tm
 
 
@@ -223,3 +226,11 @@ def test_median_with_convertible_string_raises():
     df = ser.to_frame()
     with pytest.raises(TypeError, match=msg):
         df.median()
+
+
+def test_mean_with_skipna():
+    # GH#59965 skipna=True operations don't skip NaN in FloatingArrays
+    series1 = Series({"a": 0.0, "b": 1, "c": 1})
+    series2 = Series({"a": 0.0, "b": 2, "c": 2})
+    result = series1.convert_dtypes() / series2.convert_dtypes()
+    assert notna(result.mean(skipna=True))