Please correct:  Not: ```python %timeit df['distance'] = df.apply(lambda row: haversine_cy_dtype(40.671, -73.985, row['latitude'], row['longitude']), axis=1) ``` But: ```python %timeit df['distance'] = df.apply(lambda row: haversine_cy(40.671, -73.985, row['latitude'], row['longitude']), axis=1) ``` Thank you!