6. 15 pt Jane goes to the bank to make a withdrawal, and is equally likely to nd 0, 1, or 2 customers ahead of her. The service time (in minutes) of each customer ahead, if present, is an exponential random variable with parameter A = %. (a) 8 pt Find the CDF 0f Jane's waiting time. (b) 6 pt Find the mean and the variance of Jane's waiting time. (c) 1 pt Find the probability that Jane's waiting time is between 1 and 3 minutes