The arrivals of customers at a small shop follow a homogeneous Poisson process {N(t),t0} with rate . Suppose that each customer spends a random amount of time, si in the shop, with distribution F and mean E[si]=s . If a new customer arrives while another customer is in the shop, the new customer is lost. Suppose that each customer spends a random amount of money, wi, with distribution G and mean E[wi]=w. Let W(t) be the total sales of the shop up to time t. Find limttW(t). Hint: in your solution let ti denote the time between customers who are served.