Questions about the world of GRE Math from other sources and general math related questions.
md.sharifulislam01915
Students
 
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Standard deviation

by md.sharifulislam01915 Thu Dec 26, 2013 11:55 pm

This is a QC problem. Any technique to solve this without hesitation:

Set A is a set of 10 integers, each of which is between 0 and 100.

Set B is a set of 10 integers, each of which is between 100 and 200.

Quantity A: The standard deviation of Set A.

Quantity B: The standard deviation of Set B.
tommywallach
Manhattan Prep Staff
 
Posts: 1917
Joined: Thu Mar 31, 2011 11:18 am
 

Re: Standard deviation

by tommywallach Tue Dec 31, 2013 6:23 pm

Hey MD,

Yes. SD is a function of range, not distance from zero. So you can create a range of 0 or a range of 100 with either of these sets, so you have total control over the SD. The answer is D.

You'll never need the actual equation for SD on the GRE, so if you get an SD question, it'll be more about the rules of how SD works, not the actual equation.

-t
md.sharifulislam01915
Students
 
Posts: 7
Joined: Sun Dec 08, 2013 3:38 pm
 

Re: Standard deviation

by md.sharifulislam01915 Sat Jan 04, 2014 6:15 am

Hey tommywallach,
Thanks for your generous help.Now it is clear to me.
tommywallach
Manhattan Prep Staff
 
Posts: 1917
Joined: Thu Mar 31, 2011 11:18 am
 

Re: Standard deviation

by tommywallach Mon Jan 06, 2014 12:24 am

Glad to help!

-t