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Statistics Q - 4th edition Guide 4 -Word Translations

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terp_in_umcp
 Post subject: Statistics Q - 4th edition Guide 4 -Word Translations
 Post Posted: Sat May 28, 2011 6:31 am 
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Students


Posts: 5
Hello All,

This question pertains to Statistics Q - 4th edition Guide 4 -Word Translations, pg 109.

Give the set {x,x,y,y,y,y} where x<y, Is the median greater that the arithmetic mean?

I read the explanation and it seems fine. I also tried a few numbers and it all looks fine, until i try x=0 and y=-1, in which case the answer changes.

If x=0 and y=-1, then,
Mean=(0+0+-1-1-1-1)/6=-0.6
Median=-(1-1)/2=-1.

So Mean becomes greater than Median. I noticed this usually happens when 0 is part of a set. If I totally Eliminate the 2 zeroes and say that the set has only 4 elements then the book explanation holds fine. I wanna know if there is a particular rule to follow when there are zeroes in a set?

Thanks,
Divz
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jnelson0612
 Post subject: Re: Statistics Q - 4th edition Guide 4 -Word Translations
 Post Posted: Sat May 28, 2011 3:40 pm 
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ManhattanGMAT Staff


Posts: 1857
terp_in_umcp wrote:
Hello All,

This question pertains to Statistics Q - 4th edition Guide 4 -Word Translations, pg 109.

Give the set {x,x,y,y,y,y} where x<y, Is the median greater that the arithmetic mean?

I read the explanation and it seems fine. I also tried a few numbers and it all looks fine, until i try x=0 and y=-1, in which case the answer changes.

If x=0 and y=-1, then,
Mean=(0+0+-1-1-1-1)/6=-0.6
Median=-(1-1)/2=-1.

So Mean becomes greater than Median. I noticed this usually happens when 0 is part of a set. If I totally Eliminate the 2 zeroes and say that the set has only 4 elements then the book explanation holds fine. I wanna know if there is a particular rule to follow when there are zeroes in a set?

Thanks,
Divz


Here's the problem: the question says x<y, thus, we cannot use x=0 and y=-1. I've bolded that part above. :-)

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Jamie Nelson
ManhattanGMAT Instructor
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terp_in_umcp
 Post subject: Re: Statistics Q - 4th edition Guide 4 -Word Translations
 Post Posted: Sun May 29, 2011 2:55 am 
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Students


Posts: 5
Thanks Jamie...That was a complete oversight on my part. I need to be careful with the conditions in the future :)

Thanks again,
Divz
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jnelson0612
 Post subject: Re: Statistics Q - 4th edition Guide 4 -Word Translations
 Post Posted: Mon May 30, 2011 1:06 pm 
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ManhattanGMAT Staff


Posts: 1857
No problem Divz! :-)

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Jamie Nelson
ManhattanGMAT Instructor
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