Normal distribution N(μ, σ): Bell curve, symmetric. Formula: f(x) = (1/(σ√(2π))) exp(-(x-μ)²/(2σ²)). Properties: 68-95-99.7 rule; mean=median=mode; asymptotic (never reaches axis). Applications: Heights, test scores, measurement errors, sampling distributions. Standardization: Z = (X - μ)/σ gives N(0,1). Example: Test scores N(500, 100). P(X < 600) = P(Z < 1) ≈ 0.8413 (84.13%). Solving: Calculate Z-scores. Use standard normal table. Area interpretation. Exam tip: Master empirical rule. Know normal table lookup. Practice: Various normal distribution problems.