Problem # 10: A stochastic process is said to be a compound Poisson process if it can be written in the form X (t) E Yi, where N(t) is a Poisson process and {Yi} are i.i.d. and independent of the process N(t). As an example, if customers leave a store according to a Poisson process, with Yi the amount of money spent by customer i, then X (t) represent,s the total amount of money spent by time t. Determine the mean and variance of X (t).