Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 25 Oct 2016, 08:11

Today:

Live Q&A: UCLA Adcom at 8AM PDT in Chat1 | LBS/INSEAD at 9AM in Chat1 | Expecting Interview Invites from Ross: Join Chat2 for live updates

GMAT 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

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

Practice
Pays

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If d is the standard deviation of x, y, and z, what is the

Author Message
Manager
Joined: 05 Jul 2006
Posts: 197
Followers: 1

Kudos [?]: 59 [0], given: 0

If d is the standard deviation of x, y, and z, what is the [#permalink]

Show Tags

22 Aug 2006, 13:08
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If d is the standard deviation of x, y, and z, what is the standard deviation of x+5, y+5 and z+5?

d
3d
15d
d+5
d+15
Director
Joined: 06 May 2006
Posts: 780
Followers: 3

Kudos [?]: 32 [0], given: 0

Show Tags

22 Aug 2006, 13:14
Hmmm - I think its A...

The difference of each of the values with their mean does not change, so the SD should not change as well...
Senior Manager
Joined: 14 Jul 2005
Posts: 402
Followers: 1

Kudos [?]: 26 [0], given: 0

Show Tags

22 Aug 2006, 13:21
d it is ! The answer should be A...

The difference between the mean and the actual numbers will remember the same.
Manager
Joined: 09 Jul 2006
Posts: 85
Location: India
Followers: 1

Kudos [?]: 1 [0], given: 0

Show Tags

22 Aug 2006, 13:25
mean will change
new mean = (x+5+y+5+z+5)/3 = old mean + 5
but as each of the data points has moved ahead by 5 and even the mean has moved ahead by 5, the SD (which is nothing but a representation of relative distance b/w mean and each of the data points) will remain the same.
this can be shown mathematically as well.
Hence A.
_________________

Cheers!
Prashrash.

Display posts from previous: Sort by