Assume that police estimate that 11% of drivers do not wear their seatbelts. They set up a safetyroadblock, stopping cars to check for seatbelt use. They stop 50 cars during the first hour.

a. Find themean, 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 =1p and the variance is 2=qp2.

b. How many cars do they expect to stop before finding a driver whose seatbelt is notbuckled?

The mean is

nothing

. (Round to the nearest tenth asneeded.)