Last visit was: 14 Nov 2024, 08:34 It is currently 14 Nov 2024, 08:34

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Manager
Manager
Joined: 07 Nov 2021
Posts: 52
Own Kudos [?]: 62 [5]
Given Kudos: 20
Send PM
Manager
Manager
Joined: 24 Jan 2021
Posts: 62
Own Kudos [?]: 80 [1]
Given Kudos: 898
Send PM
Manager
Manager
Joined: 07 Nov 2021
Posts: 52
Own Kudos [?]: 62 [0]
Given Kudos: 20
Send PM
Manager
Manager
Joined: 24 Jan 2021
Posts: 62
Own Kudos [?]: 80 [0]
Given Kudos: 898
Send PM
Re: Set A={9, 13, 4, 2, 7} Set B={9, 13, 4, 2, 9} Set C={9, 13, 4, 2, 4} [#permalink]
Aakash0101raj wrote:
r1smith wrote:
In order to solve this problem, I found the mean of each set and then took the absolute value of the variances of each value in the set in relation to the mean. Then I added them all together to give me an estimate of the standard deviation. That looked something like this:

Set A mean = 7 —> 2, 6, 5, 0 ==> 13

Set B mean = 7.4 —> 1.6, 5.6, 3.4, 5.4, 1.6 = 17.6

Set C mean = 6.4 —> 2.6 , 6.6, 2.4, 4.4, 2.4 = 18.4

Set D mean = 6.8 —> 2.2 , 6.2 , 2.8 , 4.8 , 0.8 = 16.8

13 < 16.8 < 17.6 < 18.4

A < D < B < C ------> Answer Choice E


This is a standard approach that everyone would follow. I was hoping for something like estimation or any simplified methods.


Then maybe pay for a tutor instead of complaining about free advice u got on the internet.
avatar
Intern
Intern
Joined: 29 Mar 2024
Posts: 1
Own Kudos [?]: 2 [2]
Given Kudos: 0
Send PM
Set A={9, 13, 4, 2, 7} Set B={9, 13, 4, 2, 9} Set C={9, 13, 4, 2, 4} [#permalink]
2
Aakash0101raj wrote:
Set A={9, 13, 4, 2, 7}
Set B={9, 13, 4, 2, 9}
Set C={9, 13, 4, 2, 4}
Set D={9, 13, 4, 2, 6}

Which of the following statement illustrates the exact order of standard deviation of these sets of numbers from the lowest to the greatest?
A. A < B < C < D
B. A < B < D < C
C. D < B < C < A
D. C < B < D < A
E. A < D < B < C


1. The common elements of all these sets are 2,4,9,13 whose average is = 28/4 =7
2. After that we check the absolute difference between the arithmatic mean (=7) and the numbers we are appending to the remaining sets i.e the last numbers in all the 5 sets.
3. The larger the difference, the larger the standard deviation.
That means, for Set A 7~7=0, Set B 9~7 =2 , Set C 4~7=3, Set D 6~7=1. (Normally we know if we append a value equal to the mean to the set, the standard deviation would decrease the most. So obviously A has the least standard deviation)
Therefore the answer would be, A<D<B<C (E)
Prep Club for GRE Bot
Set A={9, 13, 4, 2, 7} Set B={9, 13, 4, 2, 9} Set C={9, 13, 4, 2, 4} [#permalink]
Moderators:
GRE Instructor
78 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne