DennisP - thank you for the sugestion. I just happened to have a demo disc of MINITAB that I had not tried yet. Just what the Doctor ordered.
Thanks again.
Gary
I have come up against this problem in the past. The basic problem is that none of the software programs are capable of calculating a "single tailed distribution" correctly. I have had experience with a program that Boeing distributed to suppliers on the 777 program 10 or so years ago...