What is the maximum level a certain river is likely to reach over the next 25 years? (Having experienced three times a few feet of water in my house, I feel a keen personal interest in this question. ) There are many questions of the same nature: what is the likely magnitude of the strongest earthquake to occur during the life of a planned building, or the speed ofthe strongestwind a suspension bridge will have to stand? All these situations can be modeled inthesamemanner. Thevalue X of the quantity of interest (be it water t level or speed of wind) at time t is a random variable. What can be...