Answer:
15, 8, 13, 13
Explanation:
(1) mean = Σx / n = 135 / 9 = 15
(2) range = highest value - lowest value = 21 - 13 = 8
(3) mode = 13 (most repeated value in data set)
(4) for 9 values in a data set, we have that (9 + 1) / 2 = 5th number
median = 13