If you do a Google search for "Megastat" and "Excel", in the first few
links you will learn that MegaStat is a statistical add-in that is
included on the CD-ROM with Bowerman/O'Connell/Orris "Essentials of
Business Statistics" published by McGraw-Hill, and that installing from
that CD apparently does not put automatically place it in the
Tools|Add-Ins list for Excel 2003 (so that you have to Browse to find it
the first time you want to load it. Also, it appears that you can
download some version of it from
http://faculty.ed.umuc.edu/~rdickins/stat200/stat200.htm
Jerry