#### Answer

Q3=29

#### Work Step by Step

List the data set in order from least to greatest:12,17,17,18,19,21,27,29,29,36,42.The third quartile is the middle value between the median and maximum. The median is 21 and the maximum is 42. The values between are 21,27,29,29,36,42 and the middle values is 29.So the third quart is 29.