text: "half": i x[i] 1 102 2 105 ------------- Q1 = 105.5 3 106 4 109 5 110—Q2 = 110 6 112 7 115 ------------- Q3 = 116.5 8 118 9 120 More precise mathematical formulations are possible: the quartiles of the distribution of a random variable "X" can be defined as the values "x" such that: formula_1 formula_2 formula_3 With these definitions the quartiles