question 1

Question 1 (Non-anonymous question ) * Question 1 A pharmaceutical firm has discovered a new diagnostic test for a certain disease that has infected 1% of the population. The firm has announced that 95% of those infected will show a positive test result, while 98% of those not infected will show a negative test result. (i) Draw a probability tree to represent the above data. (3 marks) Find the probability that: (ii) a person has infected and test result is positive. (1 marks) (iii) a person test result is negative. (3 marks) (iv) a person has infected given that the test result is positive