Problem 8-12 The time between accidents at a congested intersection has an exponential distribution with unknown parameter , which may assume values of (1) 2/hour, (2) 3/hour, or (3) 5/hour. Complete the following for each of these levels.
(a) Determine the probability that an accident will happen within 1.5 hours.
(b) Find the expected time between accidents.
(c) Find the variance in time between accidents.