ABCDEFGHIJKLMNOPQRSTUVWXYZ Definition of Quartiles more ... The values that divide a list of numbers into quarters. In {2, 4, 4, 5, 6, 7, 8} : · Quartile 1 (Q1) = 4 · Quartile 2 (Q2), which is also the Median, = 5 · Quartile 3 (Q3) = 7 See: Median Quartiles