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Which of the following choices lists the four datasets above
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29 Jul 2018, 04:44
29 Jul 2018, 04:44
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Expert Reply
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Question Stats:
88% (00:40) correct
11% (01:19) wrong based on 69 sessions
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Dataset W: –9, –3, 3, 9
Dataset X: 2, 4, 6, 8
Dataset Y: 100, 101, 102, 103
Dataset Z: 7, 7, 7, 7
Which of the following choices lists the four datasets above in order from least standard deviation to greatest standard deviation?
(A) W, X, Y, Z
(B) W, Y, X, Z
(C) W, X, Z, Y
(D) Z, Y, X, W
(E) Z, X, Y, W
Dataset X: 2, 4, 6, 8
Dataset Y: 100, 101, 102, 103
Dataset Z: 7, 7, 7, 7
Which of the following choices lists the four datasets above in order from least standard deviation to greatest standard deviation?
(A) W, X, Y, Z
(B) W, Y, X, Z
(C) W, X, Z, Y
(D) Z, Y, X, W
(E) Z, X, Y, W
Re: Which of the following choices lists the four datasets above
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06 Aug 2018, 07:27
06 Aug 2018, 07:27
1
The five answer choices are the same. Could you please clarify the right answer?
Re: Which of the following choices lists the four datasets above
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12 Aug 2018, 16:16
12 Aug 2018, 16:16
Expert Reply
Explanation
Standard deviation is a measure of how “spread out” the numbers in a set are—in other words, how far are the individual data points from the average of all of the data points? The GRE
will not ask you to calculate standard deviation—in problems like this one, you will be able to eyeball which sets are more spread out and which are less spread out.
Since dataset Z’s members are identical, the standard deviation is zero. Zero is the smallest possible standard deviation for any set, so it must be the smallest here. You can eliminate answer choices (A), (B), and (C). Dataset Y’s members have a spread of 1 between each number, dataset X’s members are 2 away from each other, and dataset W’s members are 6 away from each other, so dataset Y has the next-smallest standard deviation (note that this is enough to eliminate answer choice (E) and choose answer choice (D)).
The correct answer is (D) Z, Y, X, W.
Standard deviation is a measure of how “spread out” the numbers in a set are—in other words, how far are the individual data points from the average of all of the data points? The GRE
will not ask you to calculate standard deviation—in problems like this one, you will be able to eyeball which sets are more spread out and which are less spread out.
Since dataset Z’s members are identical, the standard deviation is zero. Zero is the smallest possible standard deviation for any set, so it must be the smallest here. You can eliminate answer choices (A), (B), and (C). Dataset Y’s members have a spread of 1 between each number, dataset X’s members are 2 away from each other, and dataset W’s members are 6 away from each other, so dataset Y has the next-smallest standard deviation (note that this is enough to eliminate answer choice (E) and choose answer choice (D)).
The correct answer is (D) Z, Y, X, W.
