GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 19 Nov 2019, 14:25

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

The variables A, B, and C have values o

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
Joined: 11 Aug 2012
Posts: 109
Schools: HBS '16, Stanford '16
The variables A, B, and C have values o  [#permalink]

Show Tags

New post 07 Jan 2013, 11:01
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

82% (01:22) correct 18% (01:42) wrong based on 29 sessions

HideShow timer Statistics

The variables A, B, and C have values of 15, 20, 25, 30, 35, 40, and 45 with frequencies as indicated by the graphs below. For which of these frequency distributions is the median equal to the mean?
A. A only
B. B only
C. C only
D. A and B only
E. A, B, and C

Based on previous questions, I know that the answer is D. However, how could I know that graph C should not be chosen without making calculations?
Could I answer this questions just seeing the graphs? How? Thanks!

Source: http://www.grockit.com

Attachments

Median - media.png
Median - media.png [ 9.95 KiB | Viewed 1493 times ]

Retired Moderator
User avatar
B
Joined: 10 May 2010
Posts: 805
GMAT ToolKit User
Re: The variables A, B, and C have values o  [#permalink]

Show Tags

New post 07 Jan 2013, 11:25
IMO, there is no way you can see the graph of C and judge. You need to calculate for C. For A and B though symmetry should be enough.
_________________
The question is not can you rise up to iconic! The real question is will you ?
Manager
Manager
avatar
Joined: 18 Oct 2011
Posts: 78
Location: United States
Concentration: Entrepreneurship, Marketing
GMAT Date: 01-30-2013
GPA: 3.3
Re: The variables A, B, and C have values o  [#permalink]

Show Tags

New post 07 Jan 2013, 11:37
the y-axis is the # of times the frequency is included in the distribution. For the first two graphs the pattern is uniform (4,3,2,1,2,3,4) and (1,2,3,4,3,2,1). This means the mean = median.

The 3rd graph is scattered (3,3,1,2,4,1,1) and the # of frequencies are not uniform. Therefore mean cannot equal median.
e-GMAT Representative
User avatar
P
Joined: 02 Nov 2011
Posts: 2913
Re: The variables A, B, and C have values o  [#permalink]

Show Tags

New post 08 Jan 2013, 02:55
danzig wrote:
The variables A, B, and C have values of 15, 20, 25, 30, 35, 40, and 45 with frequencies as indicated by the graphs below. For which of these frequency distributions is the median equal to the mean?
A. A only
B. B only
C. C only
D. A and B only
E. A, B, and C

Based on previous questions, I know that the answer is D. However, how could I know that graph C should not be chosen without making calculations?
Could I answer this questions just seeing the graphs? How? Thanks!

Source: http://www.grockit.com

Hi,

I think you are convinced about the graphs for A & B. But you wish to know approach on how to disqualify graph C. Right!

Let's look at the frequency distribution of graph A & B.

For A

Values Frequencies
--15----------4------
--20----------3------
--25----------2------
--30----------1------
--35----------2------
--40----------3------
--45----------4------

It is quite evident that frequency distribution follows homogeneity. So For graph A, mean & median would be equal.

Now, we see graph B.

For B

Values Frequencies
--15----------1------
--20----------2------
--25----------3------
--30----------4------
--35----------3------
--40----------2------
--45----------1------

It is quite evident that frequency distribution follows homogeneity. So For graph B too, mean & median would be equal.

Now, we see graph C.

For C

Values Frequencies
--15----------3------
--20----------3------
--25----------1------
--30----------2------
--35----------4------
--40----------1------
--45----------1------

It is quite evident that frequency distribution follows heterogeneity. So for graph C, mean & median would be not be equal.

Hope this is clear to you now.

-Shalabh Jain
_________________
GMAT Club Bot
Re: The variables A, B, and C have values o   [#permalink] 08 Jan 2013, 02:55
Display posts from previous: Sort by

The variables A, B, and C have values o

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





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