Which element of variation would not be affected by adding the data value 15 to the data set {3, 5, 6, 8, 9, 10, 13, 14}? A. the lower quartile of the data set B. the median of the data set C. the upper quartile of the data set D. the range of the data set

B. The median of the data set

**Update; A. The lower quartile**

See other answer for explanation.

[3,5,6],8,9, (10,13,14) [3,5,6,8],9, (10,13,14,15)

Q1 (lower quartile) = 5 Q1 = (5 + 6) / 2 = 11/2 = 5.5

median = (8 + 9) / 2 = 17/2 = 8.5 median = 9

Q3 (upper quartile) = 13 Q3 = (13 + 14) / 2 = 27/2 = 13.5

range = 14 - 3 = 11 range = 15 - 3 = 12

I may be totally off base here ... but I am not arriving at an answer choice