"Roy" > wrote in message =
oups.com...

> ... that calculation is simple enough ..... it is just a guide to=20
> simplify things ...

D'ya suppose you could run that calculation by again?

Well, heck, Roy, if you really want to simplify things for all
of us, why don't you put up a simple web site?

Maybe here and there a little interactive spread-sheet
calculator? Like at http://samartha.net/SD/, for instance.

--
DickA