Paper 2 · Statistics
⏱ Tested in 1 exam question since 2020
Lesson 12 of 21
Statistics 12 z-scores 4
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- Find 'between' probabilities with P(a ≤ z ≤ b) = P(z ≤ b) − P(z ≤ a)
- Combine the complement and negative-z tricks inside one two-sided calculation
- Memorise the anchor P(−1.96 ≤ z ≤ 1.96) = 0.95 for all later inferential work
- Default to z-tables at HL — the empirical rule only when the question says so
Most recent exam questions
- 2020 P2 Q8(b)(i)
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