I noticed when I coded the Binomial function using the formula presented in the completing Listing 2 code, it didn't work.
That code was:
Seq.sumBy (fun k > f(!n) / (f(!k) * f(!(nk))) * p**(f(k) * (1.  p)**f(nk)))
However, the explanation text repeats the formula, but it's different and this code does work:
Seq.sumBy (fun k > f(!n) / (f(!k * !(nk))) * (p**(f(k)) * ((1.  p)**f(nk))))
It wasn't clear to me in the text that we were supposed to modify the formula from the Listing code before the unit tests would work, so I feel like this is an error.
Thanks!
Josh
