16Hit1600
Problem-Solving and Data AnalysisVery hardChange that leaves the median alone

Problem-Solving and Data Analysis practice question

The data set 5, 8, 9, 12, 15 has a median of 9. Which of the following changes to the data set would NOT change the median?

  1. A. Replacing the 15 with 100Correct
  2. B. Replacing the 9 with 11
  3. C. Removing the 5
  4. D. Adding the value 20

Answer: A. Replacing the 15 with 100

The median is the middle value. Making the largest value even larger leaves the order — and the middle — unchanged: 5, 8, 9, 12, 100 still has median 9.

Why the other answers are wrong

B. Replacing the 9 with 11
The middle value becomes 11.
C. Removing the 5
With four values (8, 9, 12, 15) the median is (9 + 12)/2 = 10.5.
D. Adding the value 20
With six values (5, 8, 9, 12, 15, 20) the median is (9 + 12)/2 = 10.5.

More Problem-Solving and Data Analysis questions

Not affiliated with the College Board. SAT is a trademark of the College Board.