Kyle Thanks for that Suggestion.
But the formula I had quoted is taken from following Websphere Tuning Guide .
a] WebSphere Conn.Pooling by Deb Erickson,Shawn Lauzon,Melissa Modjeski (PDF) Page 42 Paragraph Tuning Connection Pooling.
b] Another Big PDF (3125 kb) called as IBM WebSphere Application Server Std and Advanced Editon( Now i noticed - No authour but a collection of Tuning Papers -includes Some Notes by Gennaro(Jerry)Cuomo on Websphere Queing System)
It is from these books i got thsi formula.
I think some has to put things straight forward otherwise these PDF may be misleadeing too..