GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 24Get an Extra 30% Off Target Test Prep Plans
08:00 PM EDT
-11:59 PM EDT
Grab 30% off any Target Test Prep GRE plan during our Flash Sale and join Brian and many other students who have used Target Test Prep to score high on the GRE. Just enter the coupon code FLASH30 at checkout to save big.
The standard deviation of a list of 11 different integers,
[#permalink]
28 Aug 2020, 10:19
28 Aug 2020, 10:19
1
Expert Reply
00:00
Question Stats:
94% (00:28) correct
5% (00:43) wrong based on 36 sessions
Hide Show timer Statistics
Quantity A |
Quantity B |
The standard deviation of a list of 11 different integers, each of which is between 1 and 30, inclusive |
The standard deviation of a list of 11 different integers, each of which is between 31 and 60, inclusive |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Re: The standard deviation of a list of 11 different integers,
[#permalink]
28 Aug 2020, 10:24
28 Aug 2020, 10:24
Expert Reply
Post A Detailed Correct Solution For The Above Questions And Get A Kudos.
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Retired Moderator
Joined: 20 Aug 2020
Posts: 49
Given Kudos: 0
Re: The standard deviation of a list of 11 different integers,
[#permalink]
29 Aug 2020, 09:33
29 Aug 2020, 09:33
1
Carcass wrote:
Quantity A |
Quantity B |
The standard deviation of a list of 11 different integers, each of which is between 1 and 30, inclusive |
The standard deviation of a list of 11 different integers, each of which is between 31 and 60, inclusive |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Remind the following property about standard deviation.
If differences of consecutive data in one set \(X\) are wider than differences on consecutive data in other set \(Y\), then the standard deviation of the former set \(X\) is greater than the standard deviation of the latter set \(Y\) and we have \(SD(X) > SD(Y)\).
Consider two cases.
Case 1: \(A = \{ 1, 2, 3, \cdots , 11 \}\) and \(B = \{ 31, 33, 35, \cdots , 51 \}\).
The differences of consecutive elements in the set \(A\) are \(2 - 1 = 3 - 2 = \cdots = 11 - 10 = 1\).
The differences of consecutive elements in the set \(B\) are \(33 - 31 = 35 - 33 = \cdots = 51 - 49 = 2\).
Thus, we have \(SD(A) < SD(B)\).
Case 2: \(A = \{ 1, 3, 5, \cdots , 21 \}\) and \(B = \{ 31, 32, 33, \cdots , 41 \}\).
The differences of consecutive elements in the set \(A\) are \(3 - 1 = 5 - 3 = \cdots = 21 - 19 = 2\).
The differences of consecutive elements in the set \(B\) are \(32 - 31 = 33 - 32 = \cdots = 41 - 40 = 1\).
Thus, we have \(SD(A) > SD(B)\).
Therefore, D is the right answer.
