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05 Oct 2017, 07:40
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E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
45%
(medium)
Question Stats:
60% (01:07) correct
40%
(00:59)
wrong
based on 405
sessions
History
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Not Attempted Yet
Set X and set Y have 10 numbers each. Is standard deviation of set X greater than that of set Y ?
1) Range of set X is greater than that of set Y
2) Median of set X is greater than that of set Y
1) Range of set X is greater than that of set Y
2) Median of set X is greater than that of set Y
05 Oct 2017, 08:22
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(1) Range can be much larger if there is one or two outliers numbers in a set. But SD is not necessarily has to be bigger. Insuff.
(2) consider the two sets:
set Y = 10, 10, 20, 30, 30
Set X = 20, 20, 30, 40, 40
The SD is same though the median of set X is bigger.
again,
set Y = 10, 10, 20, 30, 30
Set X = 29, 29, 30, 31, 31
The SD is smaller in set X though the median of set X is bigger. Hence, Insuff.
(1) & (2) together also Insuff.
Ans: E.
(2) consider the two sets:
set Y = 10, 10, 20, 30, 30
Set X = 20, 20, 30, 40, 40
The SD is same though the median of set X is bigger.
again,
set Y = 10, 10, 20, 30, 30
Set X = 29, 29, 30, 31, 31
The SD is smaller in set X though the median of set X is bigger. Hence, Insuff.
(1) & (2) together also Insuff.
Ans: E.
General Discussion
07 Oct 2017, 23:18
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Harikrushna Kotadiya
Set X and Set Y have 10 numbers each. Is SD of X > SD of Y?
Statement 1:
This statement is not sufficient because for set X, even though the smallest number and largest number maybe farther than in set Y, the rest of the numbers may be closely cluttered than in set Y.
Statement 2:
Standard deviation does not depend on the actual values of the numbers but the spread of the numbers from the average. Therefore, this statement is not sufficient.
Combining statements 1 and 2 is also not sufficient because it does not give any useful information about the spread of the numbers from the average.
Therefore, answer is E.
