Statistics 1 Probability Questions, Exams of Statistics

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Statistics 1 Probability Questions

Statistics 1 Probability Answers

Statistics 1 Probability Questions 2 Xavier, Yuri and Zara attend a sports centre for their judo club’s practice sessions. The probabilities of them arriving late are, independently, 0.3, 0.4 and 0.2 respectively. (a) Calculate the probability that for a particular practice session: (i) all three arrive late; (ii) none of the three arrives late; (iii) only Zara arrives late. (1 mark) (2 marks) (2 marks) (b) Zara’s friend, Wei, also attends the club’s practice sessions. The probability that Wei arrives late is 0.9 when Zara arrives late, and is 0.25 when Zara does not arrive late. Calculate the probability that for a particular practice session: (i) both Zara and Wei arrive late; (ii) either Zara or Wei, but not both, arrives late. (2 marks) (3 marks) 6 A housing estate consists of 320 houses: 120 detached and 200 semi-detached. The numbers of children living in these houses are shown in the table. Number of children None One Two At least Total three Detached house 24 32 4l 23 120 Semi-detached house 40 37 88 35 200 Total 64 69 129 38 320 A house on the estate is selected at random. D denotes the event ‘the house is detached’. R denotes the event ‘no children live in the house’. S denotes the event ‘one child lives in the house’. T denotes the event ‘two children live in the house’. (D' denotes the event ‘not D’.)