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
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
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.

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 559 reviewsTarget Test Prep

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

Which data set has the greater standard deviation, data set

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 7187
Joined: Thu Sep 07, 2017 4:43 pmFollowed by: 23 members
by BTGmoderatorDC » Mon Nov 05, 2018 8:47 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

Which data set has the greater standard deviation, data set K or data set L?

(1) Every element in data set K is a multiple of 3.

(2) Every element in data set L is a multiple of 9.

OA E

Source: Magoosh
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 amFollowed by: 34 members
Location: Grand Central / New York
Thanked: 470 times

by Jay@ManhattanReview » Mon Nov 05, 2018 11:46 pm
BTGmoderatorDC wrote:Which data set has the greater standard deviation, dataset K or dataset L?

(1) Every element in dataset K is a multiple of 3.

(2) Every element in dataset L is a multiple of 9.

OA E

Source: Magoosh
Certainly, each statement is not sufficient since each statement gives information about only one dataset.

Combining the two statements, we get

Case 1: Say dataset K: {3, 3} and dataset L: {9, 18}

Standard deviation of dataset K = 0 since each element is the same; however, standard deviation of dataset L > 0 since each element is NOT same. The answer is dataset L.

Case 2: Say dataset K: {3, 6} and dataset L: {9, 9}

Standard deviation of dataset L = 0 since each element is the same; however, standard deviation of dataset K > 0 since each element is NOT same. The answer is dataset K.

No unique answer. Insufficient.

The correct answer: E

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: Manhattan Review India | Manhattan Review Hyderabad | Dilsukhnagar GMAT Courses | Mehdipatnam GRE Prep | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 1449
Joined: Sat Oct 09, 2010 2:16 pmFollowed by: 33 members
Thanked: 59 times

by fskilnik@GMATH » Tue Nov 06, 2018 5:52 pm
BTGmoderatorDC wrote:Which data set has the greater standard deviation, data set K or data set L?

(1) Every element in data set K is a multiple of 3.

(2) Every element in data set L is a multiple of 9.

Source: Magoosh
\[?\,\,:\,\,\,{\sigma _{\max }}\,\,\left( {K\,\,{\text{or}}\,\,L} \right)\]
\[\left( {1 + 2} \right)\,\,\,\left\{ \begin{gathered}
\,{\text{Take}}\,\,{\text{K}} = \left\{ {0,0} \right\}\,\,\,;\,\,\,L = \left\{ {0,9} \right\}\,\,\,\, \Rightarrow \,\,\,\,? = L \hfill \\
\,{\text{Take}}\,\,{\text{K}} = \left\{ {0,3} \right\}\,\,\,;\,\,\,L = \left\{ {0,0} \right\}\,\,\,\, \Rightarrow \,\,\,\,? = K \hfill \\
\end{gathered} \right.\]

The correct answer is therefore (E).


This solution follows the notations and rationale taught in the GMATH method.

Regards,
Fabio.

POST-MORTEM: in this very special situation, a careful reader may correctly mention that K=L={0} is enough to guarantee the correct answer is (E).
(We don´t want to explain this delicate issue here. We have just mentioned it because our own students will correctly think about that option at once!)
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8188
Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members
Location: Los Angeles, CA
Thanked: 43 times

by Scott@TargetTestPrep » Wed Nov 07, 2018 6:14 pm
BTGmoderatorDC wrote:Which data set has the greater standard deviation, data set K or data set L?

(1) Every element in data set K is a multiple of 3.

(2) Every element in data set L is a multiple of 9.
Every element in data set K is a multiple of 3.

Since we don't know anything about set L, statement one alone is not sufficient.

Statement Two Alone:

Every element in data set L is a multiple of 9.

Since we don't know anything about set K, statement two alone is not sufficient.

Statements One and Two Together:

Even with both statements, it's still not sufficient to answer the question. For example, if set K is {3, 6} and set L is {9, 18}, then set L has a larger standard deviation (recall that numbers are further apart from one another produce a larger standard deviation). However, if set K is {3, 3} and set L is {9, 9}, then the standard deviation of set K and set L is equal, and it's 0 (recall that a set with all numbers the same has standard deviation of 0).

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1