Answer: (X - μ)/σ.
- A X - μ
- B (X - μ)/σ
- C (X - μ)/σ²
- D σX + μ
Correct answer: B. (X - μ)/σ
Explanation: Standardisation: Z = (X−μ)/σ. If X ~ N(μ,σ²), then E[Z] = (E[X]−μ)/σ = 0 and Var(Z) = σ²/σ² = 1, giving Z ~ N(0,1). Used to find probabilities via Z-tables for any normal distribution.
Venn diagram of the universal set U with events A and B, showing the intersection (A and B), the parts unique to each event, and the complement region outside both.
Concept context
Chance, events, conditional probability, and Bayes theorem