It is currently 20 Oct 2017, 15:19

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A set has maximum number 4d above the mean and a minimum

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Director
Director
avatar
Joined: 21 Dec 2009
Posts: 582

Kudos [?]: 832 [0], given: 20

Concentration: Entrepreneurship, Finance
A set has maximum number 4d above the mean and a minimum [#permalink]

Show Tags

New post 22 Jan 2011, 06:48
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

33% (00:50) correct 67% (01:06) wrong based on 6 sessions

HideShow timer Statistics

A set has maximum number 4d above the mean and a minimum number 3d above the mean, where d (standard deviation) = 6. What is the range of this set?

A. 6
B. 18
C. 24
D. 42
E. 84

I just made a simple subtraction 4d -3d to arrive at d(6). Is this correct? Otherwise...
I wasn't sure because above and below the mean will be referring to the spread...
_________________

KUDOS me if you feel my contribution has helped you.

Kudos [?]: 832 [0], given: 20

Manager
Manager
avatar
Status: UC Berkeley 2012
Joined: 03 Jul 2010
Posts: 190

Kudos [?]: 19 [0], given: 10

Location: United States
Concentration: Economics, Finance
GPA: 4
WE: Consulting (Investment Banking)
GMAT ToolKit User
Re: Range of a set [#permalink]

Show Tags

New post 22 Jan 2011, 09:07
I would say its 42 and the wording is wrong. Max and min cannot be both above the mean...

Kudos [?]: 19 [0], given: 10

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41892

Kudos [?]: 129030 [1], given: 12187

Re: Range of a set [#permalink]

Show Tags

New post 22 Jan 2011, 10:26
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
gmatbull wrote:
A set has maximum number 4d above the mean and a minimum number 3d above the mean,
where d (standard deviation) = 6. What is the range of this set?

A:6 B:18 C:24 D:42 E84
I just made a simple subtraction 4d -3d to arrive at d(6). Is this correct? Otherwise...
I wasn't sure because above and below the mean will be referring to the spread...


Yes, it should be that "a minimum number is 3d BELOW the mean".

Now, the range of a set is the difference between the largest and smallest elements of a set. So the range of our set is (mean+4d)-(mean-3d)=7d=42.

Answer: D.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 129030 [1], given: 12187

Director
Director
avatar
Joined: 21 Dec 2009
Posts: 582

Kudos [?]: 832 [0], given: 20

Concentration: Entrepreneurship, Finance
Re: Range of a set [#permalink]

Show Tags

New post 22 Jan 2011, 11:26
yes, it's "3d below the mean" since that's a minimum. Thanks for the explanations.
_________________

KUDOS me if you feel my contribution has helped you.

Kudos [?]: 832 [0], given: 20

Re: Range of a set   [#permalink] 22 Jan 2011, 11:26
Display posts from previous: Sort by

A set has maximum number 4d above the mean and a minimum

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.