Last visit was: 23 Apr 2026, 15:45 It is currently 23 Apr 2026, 15:45
Home
Messages
Tests
Schools
Events
Close
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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,785
Own Kudos:
810,862
 [4]
Given Kudos: 105,853
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,785
Kudos: 810,862
 [4]
Which of the following sets of numbers has the greatest standard devia 31 Mar 2015, 05:35
1
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
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:

69% (00:42) correct 31% (00:52) wrong based on 262 sessions

History

Date
Time
Result
Not Attempted Yet
Which of the following sets of numbers has the greatest standard deviation?

A. 10, 11, 12
B. -3, -4, -5
C. -2, 0, 2
D. 5.1, 5.2, 5.3
E. 20, 22, 22.5


Kudos for a correct solution.
ShowHide Answer
Official Answer
C
User avatar
AmoyV
User avatar
Retired Moderator
Joined: 30 Jul 2013
Last visit: 09 Nov 2022
Posts: 244
Own Kudos:
742
 [2]
Given Kudos: 134
Status:On a mountain of skulls, in the castle of pain, I sit on a throne of blood.
Products:
My Reviews
Posts: 244
Kudos: 742
 [2]
Which of the following sets of numbers has the greatest standard devia 31 Mar 2015, 06:06
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel
Which of the following sets of numbers has the greatest standard deviation?

A. 10, 11, 12
B. -3, -4, -5
C. -2, 0, 2
D. 5.1, 5.2, 5.3
E. 20, 22, 22.5


Kudos for a correct solution.
Show more

SD of A to D in ascending order.

D<A=B<C

Now C is equally spaced and [x-avg(x)]^2=4+2+4=8

Avg of E is 21.5 and [x-avg(x)]^2=2.25+0.25+1=3.5

Answer : C
User avatar
adityadon
User avatar
Joined: 18 Mar 2014
Last visit: 28 Nov 2025
Posts: 204
Own Kudos:
152
 [2]
Given Kudos: 177
Location: India
Concentration: Operations, Strategy
Schools: INSEAD Jan '17 NTU '17 NUS '17 (D) Rutgers '18 SMU '16 (A) Weatherhead '18 (S) Broad '17 (M)
GMAT 1: 670 Q48 V35
GPA: 3.19
WE:Information Technology (Computer Software)
Schools: INSEAD Jan '17 NTU '17 NUS '17 (D) Rutgers '18 SMU '16 (A) Weatherhead '18 (S) Broad '17 (M)
GMAT 1: 670 Q48 V35
Posts: 204
Kudos: 152
 [2]
Which of the following sets of numbers has the greatest standard devia 31 Mar 2015, 10:17
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Which of the following sets of numbers has the greatest standard deviation?

A. 10, 11, 12
B. -3, -4, -5
C. -2, 0, 2
D. 5.1, 5.2, 5.3
E. 20, 22, 22.5


Kudos for a correct solution.
Show more

need to compare only option C and E
For C, Range is 4
For E ranger is only 2.5 so obvisouly it will have less SD

So anwer is C
avatar
OptimusPrepJanielle
avatar
Joined: 06 Nov 2014
Last visit: 08 Sep 2017
Posts: 1,776
Own Kudos:
1,507
 [1]
Given Kudos: 23
Expert
Expert reply
Posts: 1,776
Kudos: 1,507
 [1]
Which of the following sets of numbers has the greatest standard devia 31 Mar 2015, 10:46
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Which of the following sets of numbers has the greatest standard deviation?

A. 10, 11, 12
B. -3, -4, -5
C. -2, 0, 2
D. 5.1, 5.2, 5.3
E. 20, 22, 22.5


Kudos for a correct solution.
Show more

Standard deviation is the deviation from the mean.
Mean for set C is 0 and hence it's values have highest deviation from the mean in this set.
Hence option (C).

--
Optimus Prep's GMAT On Demand course for only $299 covers all verbal and quant. concepts in detail. Visit the following link to get your 7 days free trial account: https://www.optimus-prep.com/gmat-on-demand-course
User avatar
lipsi18
User avatar
Joined: 26 Dec 2012
Last visit: 30 Nov 2019
Posts: 131
Own Kudos:
57
 [2]
Given Kudos: 4
Location: United States
Concentration: Technology, Social Entrepreneurship
WE:Information Technology (Computer Software)
Posts: 131
Kudos: 57
 [2]
Which of the following sets of numbers has the greatest standard devia 03 Apr 2015, 14:16
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Standard Deviation:
A) 1
B) 1
C) 2
D) 0.1
E) 2 & 0.5

Now considering C & E;
C) data is well spread and its is 2 for both the digits
E) for one its 2 for other its 0.5 and SD from mean is less

Hence final answer is C

Thanks,
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,785
Own Kudos:
810,862
 [1]
Given Kudos: 105,853
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,785
Kudos: 810,862
 [1]
Which of the following sets of numbers has the greatest standard devia 06 Apr 2015, 05:41
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Which of the following sets of numbers has the greatest standard deviation?

A. 10, 11, 12
B. -3, -4, -5
C. -2, 0, 2
D. 5.1, 5.2, 5.3
E. 20, 22, 22.5


Kudos for a correct solution.
Show more

MAGOOSH OFFICIAL SOLUTION:
Attachment:
PSgreateststandarddeviation_text.PNG
PSgreateststandarddeviation_text.PNG [ 18.17 KiB | Viewed 22459 times ]
FAQ: What about answer choice (E)?

This is definitely the trickiest of the wrong answers. If you chose (E), you're not alone!

Since these lists of numbers are very short and there's the same number of elements in each--only three in each answer choice--let's use the quick way to compare SDs: compare the ranges.

The range of (C) is 2 - (-2) = 4.
The range of (E) is 22.5 - 20 = 2.5.
Since the range of E is smaller (and these are such small lists), it's pretty safe to assume that the SD is also smaller

But if that's not convincing enough, we can find the exact SD of (E)

First, what's the mean of those three numbers?
(20 + 22 + 22.5) / 3
64.5 / 3
21.5

Next, how far away is each number from the mean?

20 is 1.5 away from 21.5
22 is .5 away from 21.5
22.5 is 1 away from 21.5
This means the standard deviation is the average of .5, 1, and 1.5, which means SD = 1.

This is smaller than the average of 2, 0, and 2 from answer choice (C), which would be 4/3 = 1.33.
User avatar
AMsac123
User avatar
Joined: 08 Jun 2017
Last visit: 09 Oct 2017
Posts: 46
Own Kudos:
4
Given Kudos: 24
Posts: 46
Kudos: 4
Which of the following sets of numbers has the greatest standard devia 17 Aug 2017, 22:55
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Bunuel
Which of the following sets of numbers has the greatest standard deviation?

A. 10, 11, 12
B. -3, -4, -5
C. -2, 0, 2
D. 5.1, 5.2, 5.3
E. 20, 22, 22.5


Kudos for a correct solution.

MAGOOSH OFFICIAL SOLUTION:
Attachment:
PSgreateststandarddeviation_text.PNG
FAQ: What about answer choice (E)?

This is definitely the trickiest of the wrong answers. If you chose (E), you're not alone!

Since these lists of numbers are very short and there's the same number of elements in each--only three in each answer choice--let's use the quick way to compare SDs: compare the ranges.

The range of (C) is 2 - (-2) = 4.
The range of (E) is 22.5 - 20 = 2.5.
Since the range of E is smaller (and these are such small lists), it's pretty safe to assume that the SD is also smaller

But if that's not convincing enough, we can find the exact SD of (E)

First, what's the mean of those three numbers?
(20 + 22 + 22.5) / 3
64.5 / 3
21.5

Next, how far away is each number from the mean?

20 is 1.5 away from 21.5
22 is .5 away from 21.5
22.5 is 1 away from 21.5
This means the standard deviation is the average of .5, 1, and 1.5, which means SD = 1.

This is smaller than the average of 2, 0, and 2 from answer choice (C), which would be 4/3 = 1.33.
Show more

How about this for The OG 2017 PS 47 qn? Same logic if u apply how will we get it?

mikemcgarry Bunuel Magoosh
User avatar
mikemcgarry
User avatar
Magoosh GMAT Instructor
Joined: 28 Dec 2011
Last visit: 06 Aug 2018
Posts: 4,474
Own Kudos:
30,880
 [2]
Given Kudos: 130
Expert
Expert reply
Posts: 4,474
Kudos: 30,880
 [2]
Which of the following sets of numbers has the greatest standard devia 18 Aug 2017, 13:51
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Asac123
How about this for The OG 2017 PS 47 qn? Same logic if u apply how will we get it?
Show more
Dear Asac123,

I'm happy to respond. :-)

As a general rule, it's not the best practice to ask about one question in the thread devoted to another. If people are curious about OG 2017, PS #47, they will not be likely to find a discussion of it here. Don't just think about getting an answer to your own personal question. Think about the impact you have on all the users of this forum. A responsible approach to question-asking benefits everyone.

Also, it's not the best practice to ask the same question in multiple places. I just gave you my answer to that question in this post. Asking the same question in two different places does not send the most respectful attitude to the experts whose help you solicited, and again, other users would not find the discussion of this new question here.

Every choice you make, every action you take, has impact on others, and thus impact on how you are perceived. Furthermore, how you do anything is how you do everything. Remember that this is a public forum and anyone reading this may one day be your boss, your employee, your customer, your supplier, your competitor, etc. etc. The rewards for deeply responsible behavior yield significant payoffs in life.

Does all this make sense?
Mike :-)
User avatar
AMsac123
User avatar
Joined: 08 Jun 2017
Last visit: 09 Oct 2017
Posts: 46
Own Kudos:
4
Given Kudos: 24
Posts: 46
Kudos: 4
Which of the following sets of numbers has the greatest standard devia 18 Aug 2017, 20:12
Kudos
Add Kudos
Bookmarks
Bookmark this Post
mikemcgarry
Asac123
How about this for The OG 2017 PS 47 qn? Same logic if u apply how will we get it?
Dear Asac123,

I'm happy to respond. :-)

As a general rule, it's not the best practice to ask about one question in the thread devoted to another. If people are curious about OG 2017, PS #47, they will not be likely to find a discussion of it here. Don't just think about getting an answer to your own personal question. Think about the impact you have on all the users of this forum. A responsible approach to question-asking benefits everyone.

Also, it's not the best practice to ask the same question in multiple places. I just gave you my answer to that question in this post. Asking the same question in two different places does not send the most respectful attitude to the experts whose help you solicited, and again, other users would not find the discussion of this new question here.

Every choice you make, every action you take, has impact on others, and thus impact on how you are perceived. Furthermore, how you do anything is how you do everything. Remember that this is a public forum and anyone reading this may one day be your boss, your employee, your customer, your supplier, your competitor, etc. etc. The rewards for deeply responsible behavior yield significant payoffs in life.

Does all this make sense?
Mike :-)
Show more

Thanks Mike I understand that > i was just trying to corelate the concepts in the two questions and how it can be applied > i wanted to check if the thinking is correct or if i am missing anything. All im checking is if the above snipet of lowest range= lowest std is a general rule and can be applied to all such questions?
User avatar
AMsac123
User avatar
Joined: 08 Jun 2017
Last visit: 09 Oct 2017
Posts: 46
Own Kudos:
4
Given Kudos: 24
Posts: 46
Kudos: 4
Which of the following sets of numbers has the greatest standard devia 19 Aug 2017, 18:05
Kudos
Add Kudos
Bookmarks
Bookmark this Post
AMsac123
mikemcgarry
Asac123
How about this for The OG 2017 PS 47 qn? Same logic if u apply how will we get it?
Dear Asac123,

I'm happy to respond. :-)

As a general rule, it's not the best practice to ask about one question in the thread devoted to another. If people are curious about OG 2017, PS #47, they will not be likely to find a discussion of it here. Don't just think about getting an answer to your own personal question. Think about the impact you have on all the users of this forum. A responsible approach to question-asking benefits everyone.

Also, it's not the best practice to ask the same question in multiple places. I just gave you my answer to that question in this post. Asking the same question in two different places does not send the most respectful attitude to the experts whose help you solicited, and again, other users would not find the discussion of this new question here.

Every choice you make, every action you take, has impact on others, and thus impact on how you are perceived. Furthermore, how you do anything is how you do everything. Remember that this is a public forum and anyone reading this may one day be your boss, your employee, your customer, your supplier, your competitor, etc. etc. The rewards for deeply responsible behavior yield significant payoffs in life.

Does all this make sense?
Mike :-)

Thanks Mike I understand that > i was just trying to corelate the concepts in the two questions and how it can be applied > i wanted to check if the thinking is correct or if i am missing anything. All im checking is if the above snipet of lowest range= lowest std is a general rule and can be applied to all such questions?
Show more

hi mikemcgarry waiting patiently for ur reply
User avatar
mikemcgarry
User avatar
Magoosh GMAT Instructor
Joined: 28 Dec 2011
Last visit: 06 Aug 2018
Posts: 4,474
Own Kudos:
30,880
 [1]
Given Kudos: 130
Expert
Expert reply
Posts: 4,474
Kudos: 30,880
 [1]
Which of the following sets of numbers has the greatest standard devia 21 Aug 2017, 11:32
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
AMsac123
AMsac123


Thanks Mike I understand that > i was just trying to corelate the concepts in the two questions and how it can be applied > i wanted to check if the thinking is correct or if i am missing anything. All im checking is if the above snipet of lowest range= lowest std is a general rule and can be applied to all such questions?

hi mikemcgarry waiting patiently for ur reply
Show more
Dear AMsac123,

With all due respect, you have pressed to have me ask your question, and it's far from clear to me that you read the blog article to which I linked. If you understood everything in that blog, you would have answered your own question.

As general rule, sets with larger ranges tend to have larger standard deviations. If we were to measure the range & S.D. for every single set that, for example, has ever appeared on the GMAT, I would expect the range and S.D. to be highly correlated. Nevertheless, as always, correlation is only a statement about a general pattern, and not a statement that is true in the granular sense. Thus, if Set A has a larger range than Set B, we can't necessarily say anything about the standard deviations of these two sets.

Consider these two example sets.
Set A = {40, 40, 40, 40, 40, 60, 60, 60, 60, 60} ==> mean = median = 50, range = 20
Set B = {35, 50, 50, 50, 50, 50, 50, 50, 50, 65} ==> mean = median = 50, range = 30

Set B clearly has a much larger range. But look at how the numbers are distributed. All the numbers in Set A are at the extreme values, 10 units away from the mean, so S.D. = 10. Meanwhile, 8/10 of the numbers in Set B are at the mean, with a deviation of zero. Thus, it appears that Set B will have a much smaller S.D.

In Set A, every deviation has an absolute value of 10, so S.D. = 10
In Set B, one deviation is -15, one is +15, and other eight are zero. Sum of square deviations = 225 + 225 = 450. Average of square deviations = 45. S.D. = \(\sqrt{45}\) = \(3\sqrt{5}\) = 6.7082

Thus, Set B has a larger ranger and a smaller S.D.

Once again, I would strongly recommend reading this blog if you haven't do so already.
Standard Deviation on the GMAT
As a general rule, the way you show respect to an expert for providing help is to acknowledge explicitly everything you learned from what they already shared. If everything they shared has not answered your question, it's fine to present that as well, but to insist on what you want to know and to disregard everything else an expert tells you is relevant is disrespectful.

Does all this make sense?
Mike :-)
User avatar
AMsac123
User avatar
Joined: 08 Jun 2017
Last visit: 09 Oct 2017
Posts: 46
Own Kudos:
4
Given Kudos: 24
Posts: 46
Kudos: 4
Which of the following sets of numbers has the greatest standard devia 21 Aug 2017, 18:25
Kudos
Add Kudos
Bookmarks
Bookmark this Post
mikemcgarry
AMsac123
AMsac123


Thanks Mike I understand that > i was just trying to corelate the concepts in the two questions and how it can be applied > i wanted to check if the thinking is correct or if i am missing anything. All im checking is if the above snipet of lowest range= lowest std is a general rule and can be applied to all such questions?

hi mikemcgarry waiting patiently for ur reply
Dear AMsac123,

With all due respect, you have pressed to have me ask your question, and it's far from clear to me that you read the blog article to which I linked. If you understood everything in that blog, you would have answered your own question.

As general rule, sets with larger ranges tend to have larger standard deviations. If we were to measure the range & S.D. for every single set that, for example, has ever appeared on the GMAT, I would expect the range and S.D. to be highly correlated. Nevertheless, as always, correlation is only a statement about a general pattern, and not a statement that is true in the granular sense. Thus, if Set A has a larger range than Set B, we can't necessarily say anything about the standard deviations of these two sets.

Consider these two example sets.
Set A = {40, 40, 40, 40, 40, 60, 60, 60, 60, 60} ==> mean = median = 50, range = 20
Set B = {35, 50, 50, 50, 50, 50, 50, 50, 50, 65} ==> mean = median = 50, range = 30

Set B clearly has a much larger range. But look at how the numbers are distributed. All the numbers in Set A are at the extreme values, 10 units away from the mean, so S.D. = 10. Meanwhile, 8/10 of the numbers in Set B are at the mean, with a deviation of zero. Thus, it appears that Set B will have a much smaller S.D.

In Set A, every deviation has an absolute value of 10, so S.D. = 10
In Set B, one deviation is -15, one is +15, and other eight are zero. Sum of square deviations = 225 + 225 = 450. Average of square deviations = 45. S.D. = \(\sqrt{45}\) = \(3\sqrt{5}\) = 6.7082

Thus, Set B has a larger ranger and a smaller S.D.

Once again, I would strongly recommend reading this blog if you haven't do so already.
Standard Deviation on the GMAT
As a general rule, the way you show respect to an expert for providing help is to acknowledge explicitly everything you learned from what they already shared. If everything they shared has not answered your question, it's fine to present that as well, but to insist on what you want to know and to disregard everything else an expert tells you is relevant is disrespectful.

Does all this make sense?
Mike :-)
Show more


Thanks Mike. I dint mean to be respectful. Just wanted to get a clarity if there is a corelation between range and STD. I am sorry if you felt that way ! Thanks again :)
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,962
Own Kudos:
1,117
Posts: 38,962
Kudos: 1,117
Which of the following sets of numbers has the greatest standard devia 23 Jul 2025, 07:16
Kudos
Add Kudos
Bookmarks
Bookmark this Post
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.
Moderators:
Bunuel
Math Expert
109785 posts
Krunaal
Tuck School Moderator
853 posts