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.
The standard deviation of the dataset 10, 20, 30
[#permalink]
29 Jul 2018, 04:37
29 Jul 2018, 04:37
4
Expert Reply
8
Bookmarks
00:00
Question Stats:
59% (00:32) correct
40% (00:43) wrong based on 160 sessions
Hide Show timer Statistics
Quantity A |
Quantity B |
The standard deviation of the dataset 10, 20, 30 |
The standard deviation of the dataset 10, 20, 20, 20, 20, 20, 30 |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Re: The standard deviation of the dataset 10, 20, 30
[#permalink]
05 Aug 2018, 14:26
05 Aug 2018, 14:26
1
We do not need to work this out till the very end.
A: average= 20. x-average= -10,0,10 respectively. Square the differences- 100, 0, 100. Average of the squared differences- 200/3. Standard deviation= sqroot (200/3)
B: average=20. x-average= -10, 0,0,0,0,0, 10 respectively. Square the differences- 100, 0,0,0,0,0,100. Average of squared differences- 200/7. Standard deviation= sqroot(200/7).
Since denominator of A is smaller than that of B, A will be the larger value.
I also understand this is a very time consuming, tedious, long method. So if someone has a quicker way, please help
A: average= 20. x-average= -10,0,10 respectively. Square the differences- 100, 0, 100. Average of the squared differences- 200/3. Standard deviation= sqroot (200/3)
B: average=20. x-average= -10, 0,0,0,0,0, 10 respectively. Square the differences- 100, 0,0,0,0,0,100. Average of squared differences- 200/7. Standard deviation= sqroot(200/7).
Since denominator of A is smaller than that of B, A will be the larger value.
I also understand this is a very time consuming, tedious, long method. So if someone has a quicker way, please help
Re: The standard deviation of the dataset 10, 20, 30
[#permalink]
16 Oct 2019, 01:23
16 Oct 2019, 01:23
any easy way to do so
