When does the median of a set of numbers = the average of the set?
Do the sets have to be consecutive or evenly spaced for this rule to apply?
Median = Average when??
This topic has expert replies
-
- Master | Next Rank: 500 Posts
- Posts: 165
- Joined: Wed Mar 24, 2010 8:02 am
- Thanked: 2 times
- Followed by:1 members
GMAT/MBA Expert
- Ian Stewart
- GMAT Instructor
- Posts: 2621
- Joined: Mon Jun 02, 2008 3:17 am
- Location: Montreal
- Thanked: 1090 times
- Followed by:355 members
- GMAT Score:780
When a set is evenly spaced, the median and average are always equal. The 'converse' is *not* true; if the median and average are equal, the set may or may not be evenly spaced. For example, this set:HPengineer wrote:When does the median of a set of numbers = the average of the set?
Do the sets have to be consecutive or evenly spaced for this rule to apply?
{0,1,50,99,100}
has a median and mean of 50, but is clearly not evenly spaced.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
ianstewartgmat.com
ianstewartgmat.com
-
- Master | Next Rank: 500 Posts
- Posts: 165
- Joined: Wed Mar 24, 2010 8:02 am
- Thanked: 2 times
- Followed by:1 members
Does the evenly spaced set have to have an odd or even number of integers in the set?
or is the key simply that they are evenly spaced integers then Median = average?
or is the key simply that they are evenly spaced integers then Median = average?
GMAT/MBA Expert
- Ian Stewart
- GMAT Instructor
- Posts: 2621
- Joined: Mon Jun 02, 2008 3:17 am
- Location: Montreal
- Thanked: 1090 times
- Followed by:355 members
- GMAT Score:780
No restrictions: if a set is evenly spaced, the average equals the median.HPengineer wrote:Does the evenly spaced set have to have an odd or even number of integers in the set?
or is the key simply that they are evenly spaced integers then Median = average?
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
ianstewartgmat.com
ianstewartgmat.com