The minimum value of the set is the first one since it is an ordered set. So:
min = 5
The first quartile Q1 is the value that separates the smallest one-quarter of the data from the other three quarters. Since there are 16 values, each quarter has 4 values.
Therefore, the first quartile is the mean between the fourth (269) and the fifth values (318):
Q1 = (269 + 318)/2 = 587/2 = 293.5
Now, the median of the data set is the value dividing the set into subsets: the lower half of the data, and the upper half of the data. Since there are 16 values, the median is the mean between the eighth (447) and the ninth (513) values:
