On Sat, 24 Mar 2007 00:20:03 -0700, Toppers
wrote:

By 50% I have interpretted that as 50% in the middle of the range i.e ignore
top/bottom (lowest/highest) 25%, based on your example.


This is not how I interprete the problem:

"minimum difference on the range within this list covering 50% of
total numbers"

My interpretation is that the range can be anywhere in the list.
Maybe the example could have been better choosen.

The following 10 numbers

10,20,30,40,50,55,60,65,70,90

should give 50 and 70 in B1 and B2 respectively if you ask me.
(Not 40 and 65)

larske