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Starter. Colmnar Bruntion poll was published about people ’ s readiness for digital TV. Find the probability that a person is ready for digital TV Given that a person is ready for digital TV, find the prob that they are NZ European
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Starter Colmnar Bruntion poll was published about people’s readiness for digital TV • Find the probability that a person is ready for digital TV • Given that a person is ready for digital TV, find the prob that they are NZ European • Is being ‘NZ European’ and being ‘ready’ for digital TV independent of each other? 5718/6936 4045/5718 NO
Note 11: Probability Trees Tree diagrams are useful to display possible ways of getting given results. • If events are connected by and probabilities are multiplied • If events are connected by or probabilities are added
Example: A bag contains two white marbles and two black marbles. One marble after another is drawn (without replacement) until two black marbles have been drawn. What is the probability that exactly three draws are required?
✔ ✔ P(exactly 3 draws for 2 black marbles) = ⅓
Page 170 Exercise H