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:

When is the mean = median? [#permalink]
24 May 2012, 12:04

From my understanding, mean = median if, 1. the set consists of evenly spaced numbers 2. if all the members of the set are equal 3. set has just one number

Is there any thing else? In DS type of "is mean = median" questions, what do you have to know to be sure that mean = median?

Re: When is the mean = median? [#permalink]
24 May 2012, 19:54

bellcurve wrote:

From my understanding, mean = median if, 1. the set consists of evenly spaced numbers 2. if all the members of the set are equal 3. set has just one number

Is there any thing else? In DS type of "is mean = median" questions, what do you have to know to be sure that mean = median?

Hi,

If a series is an arithmetic progression then mean value will always be equal to median, but vice versa is not true.

Thus, any series can be formed other than the ones you have mentioned where mean = median. _________________

Re: When is the mean = median? [#permalink]
25 May 2012, 05:44

Thanks guys!

I did not say that the list that I provided is the exhaustive list. I just wanted add more to it. So if the Q is "is mean=median" What constitute sufficiency other than arithmetic progression and/or evenly spaced sets? Anything about the relationship that can be expressed in terms of range, relationship between the smallest or largest number, or the relationship between median and other numbers etc.?

Re: When is the mean = median? [#permalink]
31 May 2012, 11:03

Expert's post

Perhaps the easiest way to understand when mean = median is this one reqiurement:

1) When the distribution above the mean is symmetrical to the distribution below the mean.

So think of the middle point. Whatever pattern of data you have above the middle point is mirrored on the other side (below) the middle point.

When this happens, the mean will effectively be the same as the median (the middle number by rank).

This is satisfied when data is evenly spaced out. It's also true in other mirror-like cases.

Sure the distribution does not necessarily have to be exactly mirrored on both sides. But as long as they roughly cancel each other out, then you'll have a situation where the mean = median. _________________

Re: When is the mean = median? [#permalink]
05 Jun 2012, 04:42

Median=Mean when: 1) Numbers are in a sequence i.e. evenly spaced (and that includes consecutive numbers) 2) Only one item in the set 3) All members of the set are equal

Re: When is the mean = median? [#permalink]
05 Jun 2012, 22:23

I've always thought of it like this, if you take the average of a group of evenly spaced numbers and that result is the middle number, then voila, mean = median.

For instance,

10, 20, 30, 50, 70, 80, 90

Mean = 50 Median = 50

Last edited by vandygrad11 on 27 Mar 2013, 11:45, edited 1 time in total.

Back to hometown after a short trip to New Delhi for my visa appointment. Whoever tells you that the toughest part gets over once you get an admit is...