. What are the lower, middle, and upper quartiles of this data? 23, 15, 22, 15, 23, 15, 13, 21, 14 a. lower: 15, middle: 15, upper: 22 b.lower: 14, middle: 15, upper: 23 c.lower: 13, middle: 15, upper: 23 d.lower: 14.5, middle: 15, upper: 22.5