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.

standard deviation of Set Y

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 510
Joined: Thu Aug 07, 2014 2:24 amFollowed by: 5 members
Thanked: 3 times
by j_shreyans » Mon Oct 27, 2014 11:51 am
If the standard deviation of Set Y is 4, what are the greatest and least values that are within one standard deviation of the mean?

(1) The median of Set Y is 5.

(2) The mean of Set Y is 6.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members
Location: Palo Alto, CA
Thanked: 2867 times
GMAT Score:800

by [email protected] » Mon Oct 27, 2014 10:44 pm
Hi j_shreyans,

When a question asks about values that are within a certain number of standard deviations away from a mean, you need to know two things:
1) The standard deviation
2) The mean

In this prompt, we're given the standard deviation (in this case, 4), so we need the mean to figure out what values are within 1 SD of the mean.

Fact 1: The median = 5

This is NOT the mean, so we have no way of answering the question.
Fact 1 is INSUFFICIENT

Fact 2: The mean = 6

This IS the mean, so we CAN answer the question. since the SD is 4, the values within 1 SD of the mean are 2 to 10, inclusive.
Fact 2 is SUFFICIENT

Final Answer: B

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Tue Oct 28, 2014 1:51 am
j_shreyans wrote:If the standard deviation of Set Y is 4, what are the greatest and least values that are within one standard deviation of the mean?

(1) The median of Set Y is 5.

(2) The mean of Set Y is 6.
Let m = the mean of Set Y.
Since the SD (standard deviation) of Set Y = 4, we get:
One SD below the mean = m-4.
One SD above the mean = m+4.
Thus:
Any value between m-4 and m+4, inclusive, is within one SD of the mean.

The question stem asks for the values of m-4 and m+4.
To determine these values, we need to know the mean of Set Y.
Question stem, rephrased:
What is the mean of Set Y?

Statement 1: The median of Set Y is 5
INSUFFICIENT.

Statement 2: The mean of Set Y is 6
SUFFICIENT.

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1