continuou 6-55. The exponential distribution has a characteristic that is called the "memoryless" property. This means P(X > x) = P(X > x + x X > xo). To illustrate this, consider the calls coming into 911. Suppose that the distribution of the time between occurrences has an exponential distribution with a mean of one half hour (=0.5). a. Calculate the probability that no calls come in during the first hour. b. Now suppose that you are monitoring the call frequency, and you note that a call does not come in during the first two hours. Determine the probability that no calls will come in during the next hour. 6-56. Revisit Exercise 6-55, but examine whether it would matter when you started monitoring the 911 calls if the time between occurrences had a uniform distribution with a mean of 2 and a range of 4. a. Calculate the probability that no call comes in during the first hour. b. Now suppose that you are monitoring the call frequency, and you note that no call comes in during the first two hours. Determine the probability that no calls will arrive during the next hour. 6-57. Suppose that