• Dénombrement. (Révision) • Probabilité. • Conditionnement

BCP ST 1B
•
p E p E
p E p E
E
p n
•
P(Ω) PP(Ω)
P(∅) = 0 P(A)=1−P(A)P(A∪B) = P(A) + P(B)−P(A∩B)A⊂B=⇒P(A)6P(B)
p1, p2, . . . , pnn1
PΩ∀i∈[[1, n]], P ({ωi}) = pi
pi
•
n
•
Ak:k−k−
n
•
X
E(X) = X
ω∈Ω
X(ω)P({ω}) = X
x∈X(Ω)
x P ([X=x])
E(ϕ(X)) = X
x∈X(Ω)
ϕ(x)P([X=x])
V(aX +b) = a2V(X)
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

n
1 10
1 10
xi1 2 3 4 5 6
pi1
10
1
10
1
10
1
10
1
10
1
2
X
X
À
Á
À
Á