In 05:34 of the Prepswift video on quartiles, we find that 6 is the Q1 value. However, is 6 also in the first quartile? (i.e. is the first quartile [3, 5, 5] or [3, 5, 5, 6]?)
Additionally, given a list (1,1,1,1,2,3,3,3,3) we can find that the median is 2. Hence, Q2 = 2. However, is 2 in any quartile? If 2 is in a quartile, is 2 in the second or third quartile?