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Question 1 (7 marks): Let X= amount of time (in minutes) a postal clerk spends with their customer. The time is known to have an exponential distribution with the average amount of time spent being 4 minutes. a) (1 mark) Solve for the average number of customers the clerk will serve in a minute. b) (2 marks) Find the probability that the clerk spends between 3 to 5 minutes with a randomly selected customer. c) (2 marks) Half of customers are finished within how long? (i.e solve for the median time spent). d) (2 marks) Which is larger, the mean or the median? Explain why this is the case by referencing the shape of the distribution and your understanding of the behaviour and relationship between these values