Question

The following data set is graphed using a box plot. What is the first quartile of the data set? 67 48 39 90 33 15 80

Answer 1

The first step is to order the numbers in ascending order: 

15, 33, 39, 48, 67, 80, 90 

to find quartiles, split the data into two. the first quartile is the median of the bottom half. (second quartile is median of the whole unit, and third q is median of the top half)

i.e. the median of 15, 33, 39

which is 33 :)