Men's heights are normally distributed with a mean of 69.0 inches and a standard deviation of 2.8 inches. Women's heights are normally distributed with a mean of 63.6 inches and a standard deviation of 2.5 inches. a) What percentage of men must duck when walking through a door that is 72 inches high, to avoid hitting their head? b) What percentage of women must duck when walking through a door that is 72 inches high? c) What door height would allow at least 95% of men to walk through the door without ducking?