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06 Nov 2016, 00:37
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Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
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If 2 elements are dropped from setA {-18, -10, 0, 8, 10} what will be the % change in mean.
1) Median of the set remains same
2) The range of the set will decrease by 2
the Answer option given in my material is: Data insufficient
But I think the 1 and 2 are together important.
Reason:
Initial median is 0
Initial range: 28
Initial mean: -2
Statement 1: median doesnt change.
So median is still 0
Statement 2:
Range decreases by 2.
So -10 and 10 on either side of median are eliminated keeping Median "0" unchanged.
New set A1{-18,0,8}
New mean: -10/3
hence % change can be calculated.
WHERE AM I GOING WRONG?
1) Median of the set remains same
2) The range of the set will decrease by 2
the Answer option given in my material is: Data insufficient
But I think the 1 and 2 are together important.
Reason:
Initial median is 0
Initial range: 28
Initial mean: -2
Statement 1: median doesnt change.
So median is still 0
Statement 2:
Range decreases by 2.
So -10 and 10 on either side of median are eliminated keeping Median "0" unchanged.
New set A1{-18,0,8}
New mean: -10/3
hence % change can be calculated.
WHERE AM I GOING WRONG?
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06 Nov 2016, 02:08
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sandeepkotla
If 2 elements are dropped from setA {-18, -10, 0, 8, 10} what will be the % change in mean.
1) Median of the set remains same
2) The range of the set will decrease by 2
[/b]
1) Median of the set remains same
2) The range of the set will decrease by 2
[/b]
Question: % change in Mean if two terms are dropped from set = ?
The answer depends on which two terms are dropped from the set
Statement 1: Median of set remains same
Current Media = 0
Media will remain same only if one term smaller than 0 and one term bigger than 0 is dropped.
But the terms to be dropped may be {-18, 10} or may be {-18,8} leading to the different final means hence different final values of % change in Mean. Hence
NOT SUFFICIENT
Statement 2: Range will decrease by 2
Current Range = 10-(-18) = 28
New Range = 26 which is possible only if the smallest term is -18 and highest term is 8 in the new set after dropping two terms
i.e. two terms to be dropped may be {-10,10} or {0, 10} leading to different values of new mean hence new % change in the mean. Hence,
NOT SUFFICIENT
Combining the two statements
One term less than 0 and one term greater than 0 to be dropped (as per statement 1)
10 is to be dropped and -18 is to be retained hence
New Set will be {-18, 0, 8}
i.e. new mean = -10/3 (a Unique value) i.e. % change in mean will be a unique value as well Hence
SUFFICIENT
Answer: option C
06 Nov 2016, 02:10
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sandeepkotla
If 2 elements are dropped from setA {-18, -10, 0, 8, 10} what will be the % change in mean.
1) Median of the set remains same
2) The range of the set will decrease by 2
the Answer option given in my material is: Data insufficient
But I think the 1 and 2 are together important.
Reason:
Initial median is 0
Initial range: 28
Initial mean: -2
Statement 1: median doesnt change.
So median is still 0
Statement 2:
Range decreases by 2.
So -10 and 10 on either side of median are eliminated keeping Median "0" unchanged.
New set A1{-18,0,8}
New mean: -10/3
hence % change can be calculated.
WHERE AM I GOING WRONG?
1) Median of the set remains same
2) The range of the set will decrease by 2
the Answer option given in my material is: Data insufficient
But I think the 1 and 2 are together important.
Reason:
Initial median is 0
Initial range: 28
Initial mean: -2
Statement 1: median doesnt change.
So median is still 0
Statement 2:
Range decreases by 2.
So -10 and 10 on either side of median are eliminated keeping Median "0" unchanged.
New set A1{-18,0,8}
New mean: -10/3
hence % change can be calculated.
WHERE AM I GOING WRONG?
The highlighted part is the information of statement 1 which you are unintentionally using in statement 2 as well thereby leading you to incorrect answer choice
I hope this helps!!!
