From: Bacle on
Hi, everyone:

I am trying to see what the necessary/sufficient

conditions on a distribution , to have the mean equal

the median.

It seems like symmetry is at least sufficient; the

normal distribution obviously has this property.


In general, it would seem that if there is a value

m in the distribution such that , when removing m

,half the data points are left of m, and half are right

of m, then the mean agrees with the median. This

is weaker than ( but obviously includes the case of)

symmetry.


We would paste together (continuously)

one curve C_L left of m that integrates to 1/2,

(with limit m on the right), with a curve C_R

right of m (with limit m on the left) , so that

C_R integrates to 1/2.




Is this last condition the weakest possible to

guarantee that the mean equals the median.?


Thanks.