Question

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

Answer 1

B. The median of the data set

**Update; A. The lower quartile**
See other answer for explanation. 

Answer 2

[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