A data set contains 5 values: 11, 13, 15, 19, and x. What is the value

=>
Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

Since we have 1 variable (x) and 0 equations, D is most likely to be the answer. So, we should consider each of the conditions on their own first.

Note: if the question doesn’t include the phrase, “in increasing order”, then x could be any number. In particular, it could be greater than or less than 19.



Condition 1):
Since the median is 15, we only know that x ≥ 15.
Condition 1) is not sufficient.

Condition 2):
Since the range of the values is 8, we have 11 ≤ x ≤ 19.
Condition 2) is not sufficient.

Conditions 1) & 2):
Both conditions 1) & 2) together yield 15 ≤ x ≤ 19. But this does not tell us the exact value of x. We do not have a unique solution.
Thus, both conditions together are not sufficient.

Therefore, E is the answer.

Answer: E

If option A is only correct,15 is median then also x cannot have any value other than 17. We cannot put any other no and get a median of 17.
(11+13+15+19+x)/5=15 there is only one unknown that is x.

Hello

What you are calculating is the mean, not median.
x can be 16 and still median will be 15. x can be 2000 and still median will be 15.

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.