(27S) Probability Formulas

[rprosperi]

I agree, it's a great machine, but I constantly hit [CLR] when looking for [EXIT] after so many years of using a 42S.

The 27S nickname of the 'Do Everything Machine' is well deserved. If HP released the much rumored (back then) HP-27SII adding RPN (like they did with the 17B/17BII and 19B/19BII), this likely would have become my primary machine for years. No need to carry a 12C AND a 42S!