Yeah...this is a classic DOE exercise. I don't know any way to graphically represent this in Excel. I tried to install an oldish version of Minitab the other day but my DVD drive was acting up. Apparently, my laptop needs a Windows reinstall which will hopefully address that issue. I don't have much hope for being able to successfully install Minitab since I now have Windows 7 and so much software became immediately obsolete with it (thank you so &$*%# much Microsoft).

But if I can, I'll let you know.