Worksheets — Set 2

Probability · Random variables

Print and write your answers. Use diagrams to show thinking.

Warm-up

1. P(A) = 0.45, P(B) = 0.55. If independent, P(A∩B) = ___ 2. Binomial(n=8, p=0.5): P(X = 5) = ___ 3. E[X] for X with values {4, 6, 8} and equal probability ___

_See printable PDF for diagram._

Written practice

1. P(A) = 0.4, P(B) = 0.5. If independent, P(A∩B) = ___ 2. Binomial(n=7, p=0.5): P(X = 4) = ___ 3. E[X] for X with values {3, 5, 7} and equal probability ___ 4. Variance of a fair die roll: ___ 5. Conditional: P(A|B) when P(A∩B) = 0.14 ___ 6. Identify the distribution and parameters in context. 7. P(A) = 0.55, P(B) = 0.65. If independent, P(A∩B) = ___ 8. Binomial(n=10, p=0.5): P(X = 7) = ___

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More written practice

1. E[X] for X with values {6, 8, 10} and equal probability ___ 2. Conditional: P(A|B) when P(A∩B) = 0.2 ___ 3. P(A) = 0.7, P(B) = 0.8. If independent, P(A∩B) = ___ 4. Binomial(n=13, p=0.5): P(X = 10) = ___ 5. E[X] for X with values {9, 11, 13} and equal probability ___ 6. Conditional: P(A|B) when P(A∩B) = 0.26 ___

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Patterns and rules

1. P(A) = 1.25, P(B) = 1.35. If independent, P(A∩B) = ___ 2. Binomial(n=24, p=0.5): P(X = 21) = ___ 3. E[X] for X with values {20, 22, 24} and equal probability ___

_See printable PDF for diagram._

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Parent tip: Draw a probability table or tree