prachi18oct wrote:Set X and Y have 5 numbers, respectively.Is the S.D of X > S.D of Y?
1) Range of X > Range of Y
2) Average of X is greater than that of Y
What should be the answer here?
Statements combined:
Case 1: X = {10, 10, 10, 10, 20} and Y = {10, 10, 10, 10, 10}
Average of X = 12, with the result that one data point (20) deviates FAR from the mean.
Average of Y = 10, with the result that NO data points deviate from the mean.
Thus:
SD of X > SD of Y.
Case 2: X = {0, 13, 13, 14, 20} and Y = {0, 2, 10, 19, 19}
Average of X = 12, with the result that most of the data points (13, 13, 14) stay CLOSE to the mean.
Average of Y = 10, with the result that most of the data points (0, 2, 19, 19) deviate FAR from the mean.
Thus:
SD of X < SD of Y.
The correct answer is
E.
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