μ = E[X] σ² = E[X²] − μ² ∑(i=1→n) P(xᵢ) = θ P(A|B) = P(B|A) × P(A)/P(B) β̂ = (X'X)⁻¹X'Y R² = 1 − SSᵣₑₛ ∂f/∂x = lim h→0 H(x) = −∑p(x) log p(x) ∫₀^∞ e⁻ˣ²dx = √π/2 Γ(n) = (n−1)! χ² = ∑(Oᵢ−Eᵢ)² p < 0.05 λ = np σ = √λ F(x) = P(X≤x) z = (x−μ)/σ μ = E[X] σ² = E[X²] − μ² ∑(i=1→n) P(xᵢ) = θ P(A|B) = P(B|A) × P(A)/P(B) β̂ = (X'X)⁻¹X'Y R² = 1 − SSᵣₑₛ ∂f/∂x = lim h→0 H(x) = −∑p(x) log p(x) ∫₀^∞ e⁻ˣ²dx = √π/2 Γ(n) = (n−1)! χ² = ∑(Oᵢ−Eᵢ)² p < 0.05 λ = np σ = √λ F(x) = P(X≤x) z = (x−μ)/σ