Paper 2 · Statistics ⏱ Tested in 5+ recent exam questions Lesson 17 of 21

Statistics 17 – Confidence Intervals

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You’ll learn

  • Construct a 95% confidence interval for a mean: x̄ ± 1.96·(σ/√n)
  • Construct a 95% CI for a proportion: p̂ ± 1.96·√(p̂(1−p̂)/n)
  • Pick mean CI vs proportion CI from the question's noun (average vs percentage)
  • Interpret the interval: '95% confident the true value lies between…', with units

Most recent exam questions

  • 2025 P2 Q10(b)
  • 2024 P2 Q7(c)(i) — deferred
  • 2024 P2 Q7(c)(ii) — deferred
  • 2023 P2 Q8(b)(i)
  • 2023 P2 Q8(c)

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