Question: when skew is equal to zero a distribution is said to be
[{'answer': 'symmetric', 'provenance': [{'wikipedia_id': '28212', 'title': 'Skewness', 'start_paragraph_id': 2, 'start_character': 392, 'end_paragraph_id': 2, 'end_character': 401, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]