The average speed of vehicles on an expressway is being studied. a. Suppose observation on 50 vehicles yielded a sample mean of 65 km/hr. Assume that the standard deviation of vehicle speed is known to be 6 km/hr. Determine the two-sided 99% confidence intervals of the mean speed. b. In part (a), how many additional vehicles' speed should be observed such that the mean speed can be estimated to within + 1 km/hr with 99% confidence? C. Suppose John and Mary are assigned to collect data on the speed of vehicles on this expressway. After each person has separately observed 10 vehicles, what is the probability that John's sample mean will exceed Mary's sample mean by 2 km/hr? d. Repeat part (c) if each person has separately observed 100 vehicles instead?

The average speed of vehicles on an expressway is being studied. a. Suppose observation on 50 vehicles yielded a sample mean of 65 km/hr. Assume that the standard deviation of vehicle speed is known to be 6 km/hr. Determine the two-sided 99% confidence intervals of the mean speed. b. In part (a), how many additional vehicles' speed should be observed such that the mean speed can be estimated to within + 1 km/hr with 99% confidence? C. Suppose John and Mary are assigned to collect data on the speed of vehicles on this expressway. After each person has separately observed 10 vehicles, what is the probability that John's sample mean will exceed Mary's sample mean by 2 km/hr? d. Repeat part (c) if each person has separately observed 100 vehicles instead?

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter6: Fundamental Principles Of Traffic Flow

Section: Chapter Questions

Problem 13P

See similar textbooks

Similar questions

Consider only a single lane of a highway. Based on extensive data from an urban freeway it is assumed thatfree-flow speeds (i.e., there are no jams) can best be represented by a Normal distribution with mean andstandard deviation 119 km/h and 13.1 km/h, respectively.1. What is the probability that the speed of a randomly selected vehicle is between 100 and 120 km/h?2. What is the expected number of vehicles between two vehicles that exceed the posted speed limit of100 Km/h? You can use the Z table for calculating the final answer. You can also write your final answer in form ofR functions or as PDF/CDF of statistical distributions with correct arguments.
Question 3: (a) A section of highway is known to have a free-flow speed of 95 km/h and a capacity of 3300 veh/h. Your summer student indicates that the average time in between passing vehicles was 1.6 seconds during an hour of monitoring. If the linear speed-density relationship applies, what was the space-mean speed of the vehicles during the hour of monitoring?
7) In studying of traffic flow at a highway toll booth over a course of 60 minutes, it is determined that the arrival and departure rates are deterministic, but not uniform. The arrival rate is found to vary according to the function A(t) = 1.8+0.25t - 0.00312. The departure rate function is u(t) = 1.4 +0 .1lt. In both of these functions, t is in minutes after the beginning of the observation and (t) and „u(t) are in vehicles per minute. At what time does the maximum queue length occur? a) 49.4 min, b) 2.7 min ,c) 19.4 min, d) 60.0 min
Question 1 In studying traffic flow at a highway toll booth over a course of 60 minutes, it is determined that the arrival and departure rates are deterministic, but not uniform. The arrival rate is found to vary according to the function of A (t) = 1.8 2 +0.25t -0.0030t. The departure rate function is u(t) =1.4 + 0.11 t. In both of these functions, t is in minutes after the beginning of the observation and X(t) and u(t) are in vehicles per minutes. (i) When will the queue that forms be cleared? (ii) What time does the maximum queue length occur and what will be the corresponding queue length? (iii) Determine the total delay (iv) Estimate the average time delay per vehicle
Q.47 An observer counts 240 veh/h at a specific highway location. Assume that the vehicle arrival at the location is Poisson distributed, the probability of having one vehicle arriving over a 30- second time interval is
I need the answer as soon as possible
For a spot speed study in which 100 observations were obtained, the mean speed was 52 km/h and the standard deviation was 4.6 km/h. (BO0K: Traffic % Highway engineering, N. Gruber SI unit) What is the margin of error on the estimate of true mean speed obtained from this sample? What is a reasonable estimate of the 85th percentile speed based on the information available?
Engineering /Civil Engineering /Transportation Engineering
A data collection study found a linear speed - density relationship for a highway as follows u/65 +k/120 =1 1-Write down the speed - density ( given ) , flow - density and flow - speed models , and plot their relationships 2-raffic study has shown that the time headways between successive vehicles on this highway are exponentially distributed and that 30% of the headways between vehicles are 4 seconds or greater. Apply the traffic models derived in the question a), compute speeds and densities corresponding to this flow.
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 30-second time intervals, estimate the probability of the observer counting exactly four vehicles in an interval.
i need the answer quickly
please help in this sample problem please base your answer on the given choices thank you