Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
18 Mar 2022, 01:30
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
72% (00:47) correct
28%
(00:39)
wrong
based on 228
sessions
History
Date
Time
Result
Not Attempted Yet
What is the standard deviation of set M?
(1) Set M contains 17 terms.
(2) Set M is a set of consecutive integers
(1) Set M contains 17 terms.
(2) Set M is a set of consecutive integers
19 Mar 2022, 08:52
Kudos
Bookmarks
The answer is C -- Statement 1 doesn't tell us anything about how spread out the set is, while Statement 2 tells us we have consecutive integers, but doesn't tell us how many. I suppose it might be tempting to think that the standard deviation of a set of consecutive integers will be 1, because the numbers are 1 apart, but that actually turns out never to be true. If you take this set, for example:
{4, 5}
the standard deviation is 0.5, because each value is exactly 0.5 away from the average. If we enlarge this set to get {3, 4, 5, 6}, we've just added in two new values that are 1.5 away from the mean, which will increase the standard deviation. So the larger our set of consecutive integers, the larger our standard deviation will be, and Statement 2 is insufficient alone. But using both Statements together, we know we have 17 consecutive integers, and we don't care how big they are, just how far apart they are, so using both Statements we can answer the question.
{4, 5}
the standard deviation is 0.5, because each value is exactly 0.5 away from the average. If we enlarge this set to get {3, 4, 5, 6}, we've just added in two new values that are 1.5 away from the mean, which will increase the standard deviation. So the larger our set of consecutive integers, the larger our standard deviation will be, and Statement 2 is insufficient alone. But using both Statements together, we know we have 17 consecutive integers, and we don't care how big they are, just how far apart they are, so using both Statements we can answer the question.
General Discussion
26 Nov 2025, 08:46
Kudos
Bookmarks
Automated notice from GMAT Club BumpBot:
A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.
This post was generated automatically.
A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.
This post was generated automatically.
