Question: is the 50th percentile the mean or median
[{'answer': 'median', 'provenance': [{'wikipedia_id': '18837', 'title': 'Median', 'start_paragraph_id': 1, 'start_character': 4, 'end_paragraph_id': 1, 'end_character': 10, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18837', 'title': 'Median', 'start_paragraph_id': 19, 'start_character': 0, 'end_paragraph_id': 19, 'end_character': 571, 'bleu_score': 0.980097014099621, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4176170607362799316}, 'section': 'Section::::Finite set of numbers.\n'}]}]