Is there a function to calculate studentized range?

Question

Is there a built-in function for studentized range or do I have to build it myself?

Is there a test of normality for the studentized range?

Answer 1

I do not think there's one built-in, but it's fairly easy to write a function for it:

studentizedRange[data_List] := (Max[data] - Min[data])/StandardDeviation[data]

But I would also check out the ANOVA package for related functionality.

Answer 2

Studentizing has been dealt with adequately by Eli. As to your second question: Normality tests can be performed with DistributionFitTest.