Re: Binomial Distribution

*To*: mathgroup at smc.vnet.net*Subject*: [mg71393] Re: [mg71356] Binomial Distribution*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 16 Nov 2006 00:54:06 -0500 (EST)*Reply-to*: hanlonr at cox.net

Needs["Statistics`"] X=BinomialDistribution[10,6/10]; F[x_]:=CDF[X,x]; To have an effect, Rationalize must have a Real argument that is "close" to a rational number. Rationalize[x, 0] fill force a Rational from any Real Rationalize[Pi,0] Pi Rationalize[Pi//N,0] 245850922/78256779 Note that F[x] is not Real for a Real argument F[x] BetaRegularized[2/5, 10 - Floor[x], Floor[x] + 1] F[4.] BetaRegularized[2/5, 6, 5] Consequently, you must use N Rationalize[N[F[4]],0] 75692233/455322801 Bob Hanlon ---- Bruce Colletti <vze269bv at verizon.net> wrote: > Re Mathematica 5.2 under WinXP. > > Why doesn't the code below return a rational number? > > X = BinomialDistribution[10, 6/10]; > F[x_] := CDF[X, x]; > Rationalize@F@4 > > Thankx. > > Bruce >