Variabel acak diskrit X — distribusi probabilitas

Σ P(x) (cek)
1,000
Mean μ = E(X)
—
Variansi σ²
—
SD σ
—

E(X) = Σ x·P(x)  |  Var(X) = Σ (x−μ)²·P(x) = E(X²) − [E(X)]²