Vehicle occupancy data is taken in a high-occupancy vehicle (HOV) lane on a freeway, with the following results:
Vehicle Occupancy Number of observed vehicles
2 120
3 40
4 30
5 10

a) Compute the estimated mean and standard deviation of the vehicle occupancy in the
HOV lane. Compute the 95% confidence bounds on the estimate of the mean.
b) When the HOV lane in quesiton has an hourly volume of 900 veh/h, what is your
estimate of how many people on average are being carried in the lane? Give a 95%
confidence range.
c) If we observe the lane tomorrow and observe a volume of 900 veh/h, what is the range of
persons moved we can expect in that hour? Use a range encompassing 95% of the likely
outcomes. List any assumptions or justifications not made in part (b) but necessary in part
(c) if any