It is currently 21 Nov 2018, 08:56
My Tests

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.

The standard deviation of the dataset 10, 20, 30

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jun 2014
Posts: 4722
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 91

Kudos [?]: 1630 [0], given: 390

CAT Tests
The standard deviation of the dataset 10, 20, 30 [#permalink] New post 29 Jul 2018, 04:37
Expert's post
00:00

Question Stats:

38% (00:51) correct 61% (00:22) wrong based on 13 sessions
Quantity A
Quantity B
The standard deviation of the dataset 10, 20, 30
The standard deviation of the dataset 10, 20, 20, 20, 20, 20, 30


A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Manager
Manager
Joined: 27 Feb 2017
Posts: 150
Followers: 0

Kudos [?]: 40 [0], given: 15

Re: The standard deviation of the dataset 10, 20, 30 [#permalink] New post 05 Aug 2018, 14:26
We do not need to work this out till the very end.
A: average= 20. x-average= -10,0,10 respectively. Square the differences- 100, 0, 100. Average of the squared differences- 200/3. Standard deviation= sqroot (200/3)
B: average=20. x-average= -10, 0,0,0,0,0, 10 respectively. Square the differences- 100, 0,0,0,0,0,100. Average of squared differences- 200/7. Standard deviation= sqroot(200/7).

Since denominator of A is smaller than that of B, A will be the larger value.

I also understand this is a very time consuming, tedious, long method. So if someone has a quicker way, please help
Re: The standard deviation of the dataset 10, 20, 30   [#permalink] 05 Aug 2018, 14:26
Display posts from previous: Sort by

The standard deviation of the dataset 10, 20, 30

  Question banks Downloads My Bookmarks Reviews Important topics  


GRE Prep Club Forum Home| About| Terms and Conditions and Privacy Policy| GRE Prep Club Rules| Contact

Powered by phpBB © phpBB Group

Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.