Just a note of caution. I had Deltagraph 5.6.1. I applied the upgrade and it broke the application. The Finder says "Not supported on this platform" (I have a G5)
My suspicion is that instead of making an Universal Binary it made a Intel Only Binary by mistake. I also tried reinstalling Version 5 from scratch and doing all the upgrades with same results.
Eventually I fixed it by opening the application package (with Control-clik Show Package contents.. in the Finder). Inside instaed of the usual OSX Contents folder there was another package called Content, I open that one, copied all the stuff inside in a new folder, called that Contents and then it worked.

Quite a mess. Your mileage may wary