CASE 4.2 Refer to the distribution of daily demand for blood bags in Case 4.2 (pages 210–211). Let be the total demand over two days. Assume that demand is independent from day to day.
List the possible values for .
From the distribution of daily demand, we find that the probability that no bags are demanded on a given day is 0.202. In that light, suppose a hospital manager states, “The chances that no bags are demanded over two consecutive days is 0.404.” Provide a simple argument to the manager explaining the mistake in probability conclusion. (Hint: Use more than two days as the basis for your argument.)
What is the probability that the total demand over two days is 0? In terms of the random variable, what is ?