Drivers for a freight company make a varying number of delivery stops. The mean number of stops is 6 with standard deviation 2. Two drivers operate independently of one another.
(a) Identify the two random variables and summarize your assumptions.
(b) What is the mean and standard deviation of the number of stops made in a day by these two drivers?
(c) If each stop by one driver takes 1 hour and each stop by the other takes 1.5 hours, how many hours do you expect these two drivers to spend making deliveries?
(d) Find the standard deviation of the amount of time needed for deliveries in part (c).
(e) It is more likely the case that the driver who spends more time making deliveries also has fewer to make, and conversely that the other driver has more deliveries to make. Does this suggest that the two random variables may not meet the assumptions of the problem?