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Tarun Khanna: Junior | Next Rank: 30 Posts; Posts: 14; Joined: Wed Sep 14, 2011 1:48 amFollowed by: 1 member; Thanked: 1 times; GMAT Score:630

by Tarun Khanna » Wed Nov 02, 2011 10:17 pm

Hi

in the below ques, the OA is B....Can someone explain what is the basic underlying principle based on which the answer is B?

Is the range of a few numbers greater than $500?
(1) The median is $1,000 (2) Standard deviation is $500

thanks
tarun

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Source: Beat The GMAT — Data Sufficiency | Wed Nov 02, 2011 10:17 pm

shankar.ashwin: Legendary Member; Posts: 966; Joined: Sat Jan 02, 2010 8:06 amFollowed by: 21 members; Thanked: 230 times

by shankar.ashwin » Wed Nov 02, 2011 10:32 pm

Range is (max)-(min) in a set. Median is the middle value.

(1) says median is 1000. This alone is not sufficient for the could have any other element in it. Insuff
(2) Given SD=500. Think of SD as the average deviation between two numbers.

Now if a set had 3 numbers and given their SD=500. 2 set of numbers will have SD<500 and the other 2 will have SD>500.
If SD>500 for any set 2 numbers, their range also is > 500 Sufficient. B

You could also use SD formulas. PIck any set of numbers and try.

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gmatblood: Master | Next Rank: 500 Posts; Posts: 489; Joined: Tue Jul 05, 2011 11:10 amFollowed by: 5 members; Thanked: 28 times

by gmatblood » Wed Nov 02, 2011 11:20 pm

Tarun Khanna wrote:Hi

in the below ques, the OA is B....Can someone explain what is the basic underlying principle based on which the answer is B?

Is the range of a few numbers greater than $500?
(1) The median is $1,000 (2) Standard deviation is $500

thanks
tarun

Please structure your question in a good way.

First present the Original question, then post the OA, only in SPOILER and then bring in your query.

Thanks

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vaibhavgupta: Master | Next Rank: 500 Posts; Posts: 416; Joined: Tue Aug 30, 2011 2:18 pmFollowed by: 9 members; Location: Delhi, India; Thanked: 13 times

by vaibhavgupta » Thu Nov 03, 2011 7:52 am

gmatblood wrote:
Tarun Khanna wrote:Hi

in the below ques, the OA is B....Can someone explain what is the basic underlying principle based on which the answer is B?

Is the range of a few numbers greater than $500?
(1) The median is $1,000 (2) Standard deviation is $500

thanks
tarun
Please structure your question in a good way.

First present the Original question, then post the OA, only in SPOILER and then bring in your query.

Thanks

I second gmatblood !

If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/

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