申論題

5.(20 points) Clients come to the local post office following a Poisson process with rate λ. Each client has a complex business to do in the post office. Assuming the complexity of the business of an individual client, denoted as c, is following a uniform distribution over (0, 1). The service time of the client with complexity c in the post office is a random variable with mean 5 + 3c and variance 4, Calculate