In which range does deviation of 11, 10, 10, 10, 12 and 12 lie.
[spoiler]OA = between 0 and 3. Can someone please tell why not between 0 and 1....if Standard deviation <= Range/2[/spoiler]
In which range does deviation lie
This topic has expert replies
-
- Legendary Member
- Posts: 1799
- Joined: Wed Dec 24, 2008 3:03 am
- Thanked: 36 times
- Followed by:2 members
can u pl post the full question? pl mention the source also.goelmohit2002 wrote:In which range does deviation of 11, 10, 10, 10, 12 and 12 lie.
[spoiler]OA = between 0 and 3. Can someone please tell why not between 0 and 1....if Standard deviation <= Range/2[/spoiler]
-
- Legendary Member
- Posts: 1799
- Joined: Wed Dec 24, 2008 3:03 am
- Thanked: 36 times
- Followed by:2 members
This is complete question....
Source = one of my friends gave me this....he was given the same as part of his class assignment in GMAT coaching.
Source = one of my friends gave me this....he was given the same as part of his class assignment in GMAT coaching.
i find SD to be 0.897 and range 2.
It seems to me 'range' as mentioned in the qn. is not the range as used in statistics but range (say a<SD<b) in which the SD lies.
Now the SD, as calculated, lies between 0 and 3 and probably this choice best describes among the other available choices (I am not finding the choices in the post).
Please correct me if I misunderstand.
It seems to me 'range' as mentioned in the qn. is not the range as used in statistics but range (say a<SD<b) in which the SD lies.
Now the SD, as calculated, lies between 0 and 3 and probably this choice best describes among the other available choices (I am not finding the choices in the post).
Please correct me if I misunderstand.
- PussInBoots
- Master | Next Rank: 500 Posts
- Posts: 157
- Joined: Tue Oct 07, 2008 5:47 am
- Thanked: 3 times
I believe deviation is fancy word for difference. The actual range of deviation is 0 (10 - 10) to 2 (12-10).
- Waqas_Jameel
- Newbie | Next Rank: 10 Posts
- Posts: 7
- Joined: Wed Jul 11, 2012 8:24 am
goelmohit2002 wrote:In which range does deviation of 11, 10, 10, 10, 12 and 12 lie.
[spoiler]OA = between 0 and 3. Can someone please tell why not between 0 and 1....if Standard deviation <= Range/2[/spoiler]
I did like an explanation from some of the GMAT titans here
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
First of all, since this question does not have 5 answer choices, it's not a true GMAT question.In which range does deviation of 11, 10, 10, 10, 12 and 12 lie.
It may be possible that there's a rule that says: Standard Deviation < Range/2, I'm not sure.
However, we can be certain that Standard Deviation < Range, and that's all we need here.
Since the range = 2, we can be certain that the Standard Deviation < 2, so the standard deviation must lie between 0 and 3
Cheers,
Brent
- Waqas_Jameel
- Newbie | Next Rank: 10 Posts
- Posts: 7
- Joined: Wed Jul 11, 2012 8:24 am
Hmm.. can be .. anyways .. thanks a ton for the fast response
Brent@GMATPrepNow wrote:First of all, since this question does not have 5 answer choices, it's not a true GMAT question.In which range does deviation of 11, 10, 10, 10, 12 and 12 lie.
It may be possible that there's a rule that says: Standard Deviation < Range/2, I'm not sure.
However, we can be certain that Standard Deviation < Range, and that's all we need here.
Since the range = 2, we can be certain that the Standard Deviation < 2, so the standard deviation must lie between 0 and 3
Cheers,
Brent
GMAT/MBA Expert
- [email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi All,
The GMAT will never ask you to calculate the Standard Deviation of a group of numbers. You MIGHT be asked if a Standard Deviation gets larger or smaller when you change the group (by adding or removing elements), but you'll never be asked to do the math. In that situation, it's about understanding what SD is and how it changes.
GMAT assassins aren't born, they're made,
Rich
The GMAT will never ask you to calculate the Standard Deviation of a group of numbers. You MIGHT be asked if a Standard Deviation gets larger or smaller when you change the group (by adding or removing elements), but you'll never be asked to do the math. In that situation, it's about understanding what SD is and how it changes.
GMAT assassins aren't born, they're made,
Rich
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
I wholeheartedly agree with Rich.
To get an idea of the types of Standard Deviation questions one might encounter on the GMAT, check out these questions:
- https://www.beatthegmat.com/tricky-ds-sd ... 68907.html
- https://www.beatthegmat.com/number-quest ... 68283.html
- https://www.beatthegmat.com/sd-t247883.html
- https://www.beatthegmat.com/call-for-hel ... 53493.html
- https://www.beatthegmat.com/if-m-is-a-ne ... 48841.html
Even more here: https://www.beatthegmat.com/forums/tags/ ... -deviation
Cheers,
Brent
To get an idea of the types of Standard Deviation questions one might encounter on the GMAT, check out these questions:
- https://www.beatthegmat.com/tricky-ds-sd ... 68907.html
- https://www.beatthegmat.com/number-quest ... 68283.html
- https://www.beatthegmat.com/sd-t247883.html
- https://www.beatthegmat.com/call-for-hel ... 53493.html
- https://www.beatthegmat.com/if-m-is-a-ne ... 48841.html
Even more here: https://www.beatthegmat.com/forums/tags/ ... -deviation
Cheers,
Brent
- ganeshrkamath
- Master | Next Rank: 500 Posts
- Posts: 283
- Joined: Sun Jun 23, 2013 11:56 pm
- Location: Bangalore, India
- Thanked: 97 times
- Followed by:26 members
- GMAT Score:750
This looks more like a GRE problem than a GMAT problem.goelmohit2002 wrote:In which range does deviation of 11, 10, 10, 10, 12 and 12 lie.
[spoiler]OA = between 0 and 3. Can someone please tell why not between 0 and 1....if Standard deviation <= Range/2[/spoiler]
Let me take you through the calculations involved anyway:
average = (10+10+10+11+12+12)/6 = 65/6
std. dev. = sqrt(variance)
= sqrt((3*(5/6)^2 + 1/36 + 2*(7/6)^2)/6)
= sqrt((75/36 + 1/36 + 98/36)/6)
= sqrt((174/36)/6)
= sqrt(174/216)
= sqrt(29/36)
The answer indeed lies between 0 and 3.
Cheers
Every job is a self-portrait of the person who did it. Autograph your work with excellence.
Kelley School of Business (Class of 2016)
GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494
Kelley School of Business (Class of 2016)
GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494