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Witchiegrlie
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Mean, Medium, SD Question 27 Mar 2007, 15:30
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Hi Everyone,

This is my first post and I have a question on the following problem on mean, medium, and standard deviation:

The table below represents three sets of numbers with their respective medians, means and standard deviations. The third set, Set [A+B], denotes the set that is formed by combining Set A and Set B.



Set A ____ X (Mean) Y (Medium) Z (SD)
Set B ____ L (Mean) M (Medium) N (SD)
Set [A + B] _____ Q (Mean) R (Medium) S (SD)

If X – Y > 0 and L – M = 0, then which of the following must be true?

I. Z > N
II. R > M
III. Q > R


I only
II only
III only
I and II only
none


Is there a general rule that I can use to solve this quickly instead of listing out possible examples?

Thanks



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[email protected]
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Mean, Medium, SD Question 27 Mar 2007, 17:49
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let's consider three sets A, B , C
A= { 1,2,3,4,5,7,7} X=29/7=4.14, Y=4, Z >0
B={6,6,6,6} L=6, M=6, N =0
C={1,2,3,4,5,6,6,6,6,7,7} Q=53/11 =4.81, R=6, S=

Sets satisfy the condition X-Y >0, L-M=0, Lets evaluate the options:
I. Z > N ****true****
II. R > M ****not true***
III. Q > R *****not true***

I am not sure about the I, this holds true for these sets may not be true for other sets.

Can anybody suggest the structured approach.
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trivikram
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Mean, Medium, SD Question 27 Mar 2007, 21:32
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[email protected]
let's consider three sets A, B , C
A= { 1,2,3,4,5,7,7} X=29/7=4.14, Y=4, Z >0
B={6,6,6,6} L=6, M=6, N =0
C={1,2,3,4,5,6,6,6,6,7,7} Q=53/11 =4.81, R=6, S=

Sets satisfy the condition X-Y >0, L-M=0, Lets evaluate the options:
I. Z > N ****true****
II. R > M ****not true***
III. Q > R *****not true***

I am not sure about the I, this holds true for these sets may not be true for other sets.

Can anybody suggest the structured approach.
Show more


I think its A

Consider B ={ 1,2,3} then L=2 and M=2
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Summer3
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Mean, Medium, SD Question 28 Mar 2007, 05:12
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I go with A. :)
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Witchiegrlie
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Mean, Medium, SD Question 28 Mar 2007, 20:59
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That was my answer as well but the correct answer was E - None!

These mean, medium questions really confuse me.............
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Amardeep Sharma
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Mean, Medium, SD Question 29 Mar 2007, 00:18
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Hi, you are right answer is E!

Explanation:

I : Z>N, from set B we may know that the medium M = Mean L, but we dont have any information about the distribution, which will indicate the standard deviation from the mean. The distribution of the elements in set B can be more diversed and deviated than the distribution of set A. hence its Z>N in inconclusive

II :R > M, R is a medium of both the sets put together, while M is the medium of set A. Neither we have any information about the range of the elements in A and B, nor we know the elements of both the set. hence comparisons of mediums of individual sets with the medium of set [A+B] put together may not result anything.

III : Inconclusive for the reasons mentioned above.


regards,

Amardeep
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Witchiegrlie
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Mean, Medium, SD Question 29 Mar 2007, 21:08
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Thanks all for the explaination. I need to do more of these problems!



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Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
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Thank you for understanding, and happy exploring!