statgraphics

I perform an analysis on DOE and as it can be seen on the attached pictures, the effect of Pressure on my experiment is supposed to be negative (less oil obtained the higher the pressure) However, when checking the optimization given by the program to maximize the Oil, the value given for the...

I have many datasets consisting of grouped data -- no individual cases, only frequencies (# of cases) in each class (some open-ended upper classes). Can such data even be entered in Statistica or Statgraphics? Can it be analyzed? I can find no reference to grouped data in the help files of...