BEA 140 Quantitative Methods 2017 Exam University of Tasmania

Question 4 A factory is using two machines to produce ball bearings. The diameter of the ball bearings produced are: 0 Old machine: diameter follows a normal distribution with mean 10.00 mm and standard deviation 0.] mm. 0 New machine: diameter follows a normal distribution with mean 9.95 mm and standard deviation 0.05 mm. Ball bearings with a diameter beween 9.85 mm and 10.15 mm are acceptable. Any outside this range are unacceptable and need to be scrapped. The old machine produces 80% of the ball bearings made in the factory. b) Present the various combinations of events (new machine I old machine, and acceptable :' not acceptable) in a fully labelled tree diagram. showing marginal. conditional andjoint probabilities. {8 marks]