An observer has determined that the time headways between successive vehicles on a section of highway are exponentially distributed and that 65% of the headways between vehicles are 9 seconds or greater. If the observer decides to count traffic in 1-minute time intervals, estimate the following: a. The probability of counting exactly 4 vehicles in an interval.
b. The probability of counting 3 or more vehicles in an interval.
c. The probability of observing exactly 10 vehicles in two consecutive intervals.
d. The expected number of vehicles to experience time headway between 10?second and 20-second.
e. The average time headway of this traffic stream