Originally Posted by Koyote

First day of probability theory in my Sophomore year stats class: professor says, "Suppose I toss a coin nine times, and it comes up heads each time. What are the odds it comes up heads on the tenth toss?"

Answers were all over the place. Some people thought the probability of the coin coming up heads the tenth time was very low, others thought very high. Of course, the correct answer is that the probability was .5, or one in two. Each coin toss is a random event, as is each encounter with angry and aggressive motorists -- assuming the rider is not triggering the anger through some out-of-the-ordinary actions.