Previous Up Next

8.4.2  Fonction de répartition de la loi binomiale : binomial_cdf

Lorsqu’une variable aléatoire X suit une loi binomiale B(n,p), on a :
binomial_cdf(n,p,x)=Proba(Xx)=
binomial(n,0,p)+...+binomial(n,floor(x),p).
binomial_cdf(n,p,x,y)=Proba(xXy)=
binomial(n,ceil(x),p)+...+binomial(n,floor(y),p).
On tape :

binomial_cdf(4,0.5,2)

On obtient :

0.6875

On peut vérifier que :

binomial(4,0,0.5)+binomial(4,1,0.5)+binomial(4,2,0.5)
=0.6875

On tape :

binomial_cdf(2,0.3,1)

On obtient :

0.91

On tape :

binomial_cdf(2,0.3,1,2)

On obtient :

0.51

Previous Up Next