1.

Assume that police estimate that 12% of drivers do not wear their seatbelts. They set up a safety roadblock, stopping cars to check for seatbelt use. They stop 40 cars during the rst hour. 3. Find the mean, variance, and standard deviation of the number of drivers expected not to be wearing seatbelts. Use the fact that the mean of a geometric distribution is p = and the variance is 52 = 12 P p b. How many cars do they expect to stop before nding a driver whose seatbelt is not buckled? Find the indicated probabilities using the geometric distribution, the Poisson distribution. or the binomial distribution. Then determine if the events are unusual. If convenient. use the appropriate probability table or technology to nd the probabilities. A newspaper nds that the mean number of typographical errors per page is four. Find the probability that (a) exactly six typographical errors are found on a page, (b) at most six typographical errors are found on a page, and (c) more than six typographical errors are found on a page. (a) P(exactly six typographical errors are found on a page) = D (Round to four decimal places as needed.)