[New Quizzes] Add probability distribution functions to library for Formula question types in New Quizzes

[cvalle]

I am preparing to write Quizzes for my future stats students in canvas. In order for this to work I am in need of a few more standard functions in the library for Formula questions:

cdf functions for the Normal, T, Binomial and Chi-square distributions.

Inverse functions for Normal and T.

Sample standard deviation would also be nice.

Thanks for your consideration!

[mkrasnow]

Yes!  This is exactly what I need (and was looking for).  It is impossible to compute, e.g., the normal CDF from the currently available functions.  It would be great if these CDF functions could be added.