Find all School-related info fast with the new School-Specific MBA Forum

It is currently 02 Sep 2015, 06:05
GMAT Club 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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Standard Deviation

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
User avatar
Joined: 02 Apr 2006
Posts: 94
Followers: 1

Kudos [?]: 22 [0], given: 0

Standard Deviation [#permalink] New post 05 Nov 2007, 05:45
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

I am a struggling gmater with MATH.. desperately..... please help me again to understand why the answer is so..

Q. If a cetain sample of data has a mean of 20.0 and a standard deviation of 3.0, which of the following values is more than 2.5 standard deviations from the mean?

1) 12.0
2) 13.5
3) 17.0
4) 23.5
5) 26.5

and the answer is 1)... please help me understand the solution...
Thank you for your sharings, in advance..
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Senior Manager
Senior Manager
avatar
Joined: 19 Feb 2007
Posts: 327
Followers: 1

Kudos [?]: 24 [0], given: 0

 [#permalink] New post 05 Nov 2007, 05:48
2.5 SD = 2.5 * 3 = 7.5

more than 2.5 standard deviations from the mean is
either less than 20 - 7.5 = 12.5, or

greater than 20 + 7.5 = 27.5

So ans A
Manager
Manager
User avatar
Joined: 02 Apr 2006
Posts: 94
Followers: 1

Kudos [?]: 22 [0], given: 0

so... [#permalink] New post 05 Nov 2007, 05:56
2.5 standard deviation from the mean
means
2.5 * SD??

Ah ah.. thank you.. so much..

sidbidus wrote:
2.5 SD = 2.5 * 3 = 7.5

more than 2.5 standard deviations from the mean is
either less than 20 - 7.5 = 12.5, or

greater than 20 + 7.5 = 27.5

So ans A
so...   [#permalink] 05 Nov 2007, 05:56
Display posts from previous: Sort by

Standard Deviation

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.