Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Question on SD

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 195
Joined: Sun Oct 21, 2007 4:33 am
Thanked: 10 times
by sankruth » Wed Jan 16, 2008 12:03 pm
If M is a negative integer and K is a positive integer, which of the following could be the Standard Deviation of the set {-7, -5, -3, M, 0, 1, 3, K, 7}

I. -1.5
II -2
III 0

A - I only
B - II only
C - III only
D - I and III only
E - None
Top
Join the discussion
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 158
Joined: Mon Dec 03, 2007 8:32 am
Thanked: 7 times

by StarDust845 » Wed Jan 16, 2008 12:09 pm
Is the answer E?

Calista.
Top
Join the discussion
Master | Next Rank: 500 Posts
Posts: 195
Joined: Sun Oct 21, 2007 4:33 am
Thanked: 10 times

by sankruth » Wed Jan 16, 2008 12:25 pm
StarDust845 wrote:Is the answer E?

Calista.
Sorry, I forgot to ask the main question... Is there a way to solve it in under 2 minutes?

By the way E is correct!
Top
Join the discussion
User avatar
GMAT Instructor
Posts: 3224
Joined: Tue Jan 08, 2008 2:40 pmFollowed by: 614 members
Location: Toronto
Thanked: 1710 times
GMAT Score:800

Re: Question on SD

by Stuart@KaplanGMAT » Wed Jan 16, 2008 12:33 pm
sankruth wrote:If M is a negative integer and K is a positive integer, which of the following could be the Standard Deviation of the set {-7, -5, -3, M, 0, 1, 3, K, 7}

I. -1.5
II -2
III 0

A - I only
B - II only
C - III only
D - I and III only
E - None
Just curious - where is this question from? I've never seen a GMAT question that asked the test taker to calculate SD.

On the other hand, we don't actually need to do any calcuations to answer this question, we just need to understand how SD works.

SD is a measurement of how spread out the members of a set are. Since SD really measures distance, there's no such thing as a negative SD.

Further, unless all the members of the set are identical, the SD will always be greater than 0.

So, we can't have negative SD, statements I and II are out. Some of the members of the set are different, so statement III is out. Pick (e), none of the above.
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
Join the discussion
Master | Next Rank: 500 Posts
Posts: 195
Joined: Sun Oct 21, 2007 4:33 am
Thanked: 10 times

by sankruth » Thu Jan 17, 2008 2:18 am
Sorry, I dont know the source of this question. Got a small set of questions on Statistics from a friend.

Thanks for your explanation, Stuart!
Top
Join the discussion