Computing Probabilities of a Trinomial Distribution

Version 1.0
© Bin Wang 2008.

The following program provides a tool to compute the trinomial probabilities with formula

f(x1, x2, x3; n, p1, p2, p3) = P(X1=x1, X2=x2, X3=x3) = n!/(x1!.x2!.x3!).p1x1.p2x2.p3x3

where x1+x2+x3=n and p1+p2+p3=1 and
n: the total number of trials; ( n=5,10,15,20,30,60).
x1: number of times that outcome 1 was observed;
x2: number of times that outcome 2 was observed; ( x2=0,1,2,3).
x3: number of times that outcome 2 was observed; ( x3=0).
p1: probability that outcome 1 will be observed in one trial;
p2: probability that outcome 2 will be observed in one trial; ( p2=0.05, 0.10, 0.15, 0.20, 0.25, 0.30).
p3: probability that outcome 3 will be observed in one trial; ( p3=0.05, 0.10, 0.15, 0.20).
n =

x2 = ; x3 = .

p2 = ; p3 = .


Invalid parameter!: n =
Invalid parameter: x2 =
Invalid parameter: x3 =
Invalid parameter: p2 =
Invalid parameter: p3 =