BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Standart deviation

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 258
Joined: Thu Aug 07, 2008 5:32 am
Thanked: 16 times

Re: Standart deviation

by x2suresh » Sun Feb 22, 2009 6:38 am
4meonly wrote:OA D

standard deviation will not change if you add/subtract same number to list.

s-2,r-2, t-2
0 =s-s , r-s, t-s
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 30
Joined: Sun Oct 26, 2008 5:42 pm
Thanked: 5 times

Re: Standart deviation

by Ossa » Mon Feb 23, 2009 4:03 pm
Just to clarify, Standard deviation is a measure of dispersion of points around a certain mean and that is why subtracting the same number from all values only shifts the mean but dispersion remains the same and so the standard deviation does not change.
4meonly wrote:OA D
Ossa Elhadary, PhD, CISA, PMP
Math Specialist
Test Prep New York
maximize your score, minimize your stress

www.testprepny.com
[email protected]
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 137
Joined: Thu Jan 08, 2009 1:27 am
Thanked: 7 times

by welcome » Mon Feb 23, 2009 7:29 pm
x2suresh,
Can you please tell me, in your solution, how come

0 =s-s , r-s, t-s
is considered as

0,s-t,s-r ???

because for making then equal we need to multiply by -1, which will chnage SD.

Please someone help me in this concept.
Shubham.
590 >> 630 >> 640 >> 610 >> 600 >> 640 >> 590 >> 640 >> 590 >> 590
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 258
Joined: Thu Aug 07, 2008 5:32 am
Thanked: 16 times

by x2suresh » Mon Feb 23, 2009 7:40 pm
welcome wrote:x2suresh,
Can you please tell me, in your solution, how come

0 =s-s , r-s, t-s
is considered as

0,s-t,s-r ???

because for making then equal we need to multiply by -1, which will chnage SD.

Please someone help me in this concept.

it won't make any difference.

distance between r and s = distance between s and t


Its like you are moving all dispersion points values from poistive teritory into negative terriotory, but S.D will be the same.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 137
Joined: Thu Jan 08, 2009 1:27 am
Thanked: 7 times

by welcome » Mon Feb 23, 2009 7:46 pm
Thanks, x2suresh, That was a quick point to note for me.
Shubham.
590 >> 630 >> 640 >> 610 >> 600 >> 640 >> 590 >> 640 >> 590 >> 590
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1