The ShowStat command displays the results of the last regression or summary statistics command in a dialog box. The full list of such commands is: CubicReg, ExpReg, LinReg, LnReg, Logistic, MedMed, OneVar, PowerReg, QuadReg, QuartReg, SinReg, and TwoVar.
For regressions, ShowStat first displays the general form of the regression (for instance, y=a*x+b), then the values of the parameters (a and b, in this case); LinReg also outputs the value of corr, and all of them but MedMed display the value of R2. For OneVar and TwoVar, ShowStat merely displays the list of system variables modified, along with their values.
If there are no statistics to display (for instance, if none of these commands have been used since the calculator was last reset), ShowStat will display "No stat variables" in the dialog box. The calculator also automatically deletes the statistics if the variables they were calculated from are modified or deleted.
ShowStat might not always be the best choice to display these results. For instance, when doing a regression, looking at regeq(x) (assuming x is undefined) will give you the entire equation at once. In a program especially, you might want to display the output in a different way than with ShowStat.