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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

ds - mean of 2 sets [#permalink]
25 Oct 2005, 10:45

00:00

A

B

C

D

E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct
0% (00:00) wrong based on 0 sessions

If the two sets have an equal number of
numbers, is the mean of set Q lower than the
mean of set P?

(1) Set Q consists of consecutive even integers
and set P of consecutive odd integers.
(2) The median of Q is higher than the mean of P. _________________

If your mind can conceive it and your heart can believe it, have faith that you can achieve it.

(1) example consecutives
Q 2, 4, 6 and P 3, 5, 7 mean Q<P
Q 4, 6, 8 and P 3, 5, 7 mean Q>P
insuff.

(2) med Q > mean P
Q 1, 9, 10 and P 2, 4, 6 mean Q>P
Q -5, 5, 6 and P 3, 4, 5 mean Q<p
insuff.

(1)&(2)
from (1) we know that the sets are consecutive and therefore the mean = median!
from (2) we know that the median of Q is larger than mean of P and therefore the mean of Q is larger then the mean of P. suff.

Given both sets have equals #items.
Q: Qmean (Qm) < Pmean (Pm) ?

1) Take sets P=consec even int's, Q= consec odd int's
P{-4,-2,0,2} and Q{1,3,5,7} result in Qm>Pm
However, P{2,4,6} and Q{-5,-3,-1} result in Qm<Pm
NOT SUFF => BCE

2) says Qmed>Pm
P{1,2,3} and Q{1,3,5} satisfy the condition Qmed>Pm (3>2) and result in Qm>Pm (3>2)
P{-1,0,1} and Q{-3,1,1} satisfy the condition Qmed>Pm (1>0) and result in Qm<Pm (-1/3<0)
NOT SUFF => CE

1+2)
Median and Mean of consecutive integers (odd or even) is the same
E.g. {1,3,5,7} med=4, mean=4
So if Median of a set Q of consec int's is > than mean of another set P(doesn't matter what it's content) then it follows that Mean of such set Q must be > than mean of P.
Effectively saying Qm>Pm when Qmed>Pm given Q is set of consec int's
Some examples: P{-4,-2,0}&Q{1,3,5}; P{-4,-2,0,2}&Q{-3,-1,1,3}
SUFF => C

Re: ds - mean of 2 sets [#permalink]
26 Oct 2005, 00:57

christoph wrote:

If the two sets have an equal number of numbers, is the mean of set Q lower than the mean of set P?

(1) Set Q consists of consecutive even integers and set P of consecutive odd integers. (2) The median of Q is higher than the mean of P.

Q = {2,4,6} mean = 4, and P = {301,303,305} mean = 303
=> Mean of Q < Mean of p
But if q={302,304,306} mean = 304, and p = {1,3,5} mean = 3, then mean of Q > Mean of p.

So statement 1 is not suff.

Statement 2. Let Q = {1,2,3} median = 2 and mean = 2
Let P = {3,1,2} medain =1 and mean = 2 , statement 2 is not suff.

Combining both. P = Set of consecutive odd int.
Q = Set of consecutive even integers.
No of terms in p and q are same.
Median of p is greater than median of Q
If the no of terms are same, and the middle value of p is greater than q and p being consecutive odd and q being consecutive even, then each corresponding elements of p is greater than its corresponding element in Q. So the mean of p is also greater than mean of Q.Hence C.

gmatclubot

Re: ds - mean of 2 sets
[#permalink]
26 Oct 2005, 00:57

Hey, Last week I started a few new things in my life. That includes shifting from daily targets to weekly targets, 45 minutes of exercise including 15 minutes of yoga, making...

This week went in reviewing all the topics that I have covered in my previous study session. I reviewed all the notes that I have made and started reviewing the Quant...

I started running as a cross country team member since highshcool and what’s really awesome about running is that...you never get bored of it! I participated in...