Find all School-related info fast with the new School-Specific MBA Forum

It is currently 21 Oct 2014, 18:09

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A store sells coats at different prices. Is the deviation of

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
avatar
Joined: 08 Aug 2005
Posts: 251
Followers: 1

Kudos [?]: 9 [0], given: 0

A store sells coats at different prices. Is the deviation of [#permalink] New post 22 Jul 2006, 05:31
A store sells coats at different prices. Is the deviation of the price less than $120?

1) The median of the price is $90
2) The range of the price is $ 100
Intern
Intern
avatar
Joined: 14 May 2006
Posts: 32
Followers: 0

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

I will go with B [#permalink] New post 22 Jul 2006, 12:20
I will go with B
1) Median 90 means (80,90, 100) or (80, 90, 600) deviation can be anything.
2) Range means difference betwen first and last element if it si 100 then devaition can not be more than 100 So ans is B.

Pravin
Director
Director
User avatar
Joined: 28 Dec 2005
Posts: 761
Followers: 1

Kudos [?]: 8 [0], given: 0

Re: Price of coats [#permalink] New post 22 Jul 2006, 15:05
getzgetzu wrote:
A store sells coats at different prices. Is the deviation of the price less than $120?

1) The median of the price is $90
2) The range of the price is $ 100


What is meant by "deviation" here? Is it the same as standard deviation?
If it is then I don't think we can solve this (E).
Senior Manager
Senior Manager
avatar
Joined: 09 Aug 2005
Posts: 286
Followers: 1

Kudos [?]: 1 [0], given: 0

Re: Price of coats [#permalink] New post 23 Jul 2006, 13:16
Futuristic wrote:
getzgetzu wrote:
A store sells coats at different prices. Is the deviation of the price less than $120?

1) The median of the price is $90
2) The range of the price is $ 100


What is meant by "deviation" here? Is it the same as standard deviation?
If it is then I don't think we can solve this (E).


we do not need to solve this one for SD

I think B too

oa please
SVP
SVP
avatar
Joined: 30 Mar 2006
Posts: 1741
Followers: 1

Kudos [?]: 28 [0], given: 0

 [#permalink] New post 26 Jul 2006, 01:32
E . If we care looking for Standard deviation.
B If we are looking only for the deviation
Intern
Intern
avatar
Joined: 21 Jul 2006
Posts: 27
Followers: 0

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

 [#permalink] New post 26 Jul 2006, 01:53
jaynayak wrote:
E . If we care looking for Standard deviation.
B If we are looking only for the deviation


Even in terms of STDEV ...

Consider Example JUST 3 PRICES ARE USED: 0$ 90$ 100$

RANGE: 100
MEDIAN: 90
STDEV: 55

SO NIETHER STATEMENT IS SUFFICIENT, whether Its asked STDEV or Just Deviation.... MEANABSDEV ... etc... :))
_________________

Be Supportive and Helpful! And Everything Will Bounce Back to You!

Senior Manager
Senior Manager
avatar
Joined: 12 Mar 2006
Posts: 371
Schools: Kellogg School of Management
Followers: 2

Kudos [?]: 28 [0], given: 3

 [#permalink] New post 26 Jul 2006, 19:42
yes the range is max - min and standard deviation will not be > range...i thought...isnt it ? Please correct me...it is not true
CEO
CEO
User avatar
Joined: 20 Nov 2005
Posts: 2922
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008
Followers: 15

Kudos [?]: 81 [0], given: 0

 [#permalink] New post 26 Jul 2006, 21:34
B

Even if SD is asked then also answer should be B. SD is ralative to mean. It doesn't matter values in the set are high or low. SD is the measure of dispersion of values of a set measured from mean.

Correct me if I am wrong.
_________________

SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008

Intern
Intern
avatar
Joined: 20 May 2005
Posts: 20
Location: Los Angles
Followers: 0

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

 [#permalink] New post 26 Jul 2006, 21:53
ps_dahiya wrote:
B

Even if SD is asked then also answer should be B. SD is ralative to mean. It doesn't matter values in the set are high or low. SD is the measure of dispersion of values of a set measured from mean.

Correct me if I am wrong.


Thanks ps_dahiya, I was also thinking the same...
Ans should be B.
Senior Manager
Senior Manager
avatar
Joined: 22 May 2006
Posts: 375
Location: Rancho Palos Verdes
Followers: 1

Kudos [?]: 18 [0], given: 0

Re: Price of coats [#permalink] New post 26 Jul 2006, 22:29
Here's my 2cents about deviation, variance, and standard deviation.

Let, set X = {X1,X2,....,Xn} (asscending order)
no matter what the value of a term is sum of each term's deviation is "0"
deaviation of 1st term = X1-mean
deaviation of 2nd term = X2-mean
....
deaviation of nth term = Xn-mean
Sum of deviations = X1+X2+....+Xn - (mean*n) = Total - Total = 0
Range = Xn-X1
Max. deviation = Xn - mean
Min. deviation = X1 - mean
Range > Max. devation > Min. deviation ('cuz mean < Xn)
(Except, when range = 0, Range = deviation = 0)

Standard deviation = sqrt(variance)

Square of 1st term's deviation : (X1-mean)^2
Square of 2nd term's deviation : (X2-mean)^2
.....
Square of nth term's deviation : (Xn-mean)^2

Variance
= [(X1^2-2X1*mean + mean^2)+ .... +(Xn^2-2Xn*mean + mean^2)]/n
= [(X1^2+X2^2...+Xn^2) - 2(X1+X2+..+Xn)(mean) + n*mean^2]n
= (X1^2+X2^2...+Xn^2)/n - 2(X1+X2+..+Xn)(mean)/n + mean^2
= (X1^2+X2^2...+Xn^2)/n - 2[(X1+X2+..+Xn)/n](mean) + mean^2
= (X1^2+X2^2...+Xn^2)/n - 2[mean](mean) + mean^2
= (X1^2+X2^2...+Xn^2)/n - mean^2
= Average of square of each term - mean^2 > 0

Standard devation
= sqrt(variance )

Range > Standard deviation
(Except, when range = 0, Range = varicance = standard deviation = 0)
Range = Xn-X1
Variance = (X1^2+X2^2...+Xn^2)/n - mean^2
Standard deviation = sqrt((X1^2+X2^2...+Xn^2)/n - mean^2)
Range - standard deviation
= Xn-X1 - sqrt((X1^2+X2^2...+Xn^2)/n - mean^2)
Square both side.
(Range - standard deviation)^2
= (Xn-X1 - sqrt((X1^2+X2^2...+Xn^2)/n - mean^2))^2
(Range - standard deviation)^2
= (Xn-X1)^2 - 2(Xn-X1)sqrt((X1^2+X2^2...+Xn^2)/n - mean^2))^2
Stuck here.. will try tomorrow. :oops:



Logical proof:
Purpose of those measures - deviation and standard deviation - is to see how far each term is from the mean.
Range is max. distance in a set.
Thus, Range is greater than or equal to those measures.



getzgetzu wrote:
A store sells coats at different prices. Is the deviation of the price less than $120?

1) The median of the price is $90
2) The range of the price is $ 100



1.
the deviation means each deviation.
S1. median of the price is $90. insuff.
S2. range of the price is $100.
tells that Max. deviation is less than $100 suff.
Hence, B.

2.
if question is asking about sum of each deviation.
Then, this question turns to be trivial. Doesn't need to consider S1 and S2.
0 is less than 120.
Hence, D.

3.
if question is asking about standard deviation.
1) The median of the price is $90 insuff.
2) The range of the price is $ 100 suff.
Range is always greater than standard deviation.(Except when range = 0)
Hence, B.
_________________

The only thing that matters is what you believe.

Re: Price of coats   [#permalink] 26 Jul 2006, 22:29
    Similar topics Author Replies Last post
Similar
Topics:
A store selling price..... monirjewel 2 28 Oct 2010, 21:28
A stationery store sells pens and pencils. If the price of bibha 3 02 Aug 2010, 19:37
A store sells pens and pencils. Provided that the price of bmwhype2 2 30 Oct 2007, 08:17
A store sells coats at different price. Is the deviation of getzgetzu 2 05 May 2006, 22:31
Display posts from previous: Sort by

A store sells coats at different prices. Is the deviation of

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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

Powered by phpBB © phpBB Group and phpBB SEO

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®.