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MindTap Engineering for Garber/Hoel's Traffic and Highway Engineering, 5th Edition, [Instant Access], 1 term (6 months)
5th Edition
ISBN: 9781305581159
Author: Nicholas J. Garber; Lester A. Hoel
Publisher: Cengage Learning US
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Question
Chapter 4, Problem 3P
To determine
(a)
The number of spot speed observations collected
To determine
(b)
The sample size
Expert Solution & Answer
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Speed data collected on an urban roadway yielded a standard deviation in speeds
of 4.8 mi/h.
(a) If an engineer wishes to estimate the average speed on the roadway at a 95%
confidence level so that the estimate is within 2 mi/h of the true average, how
many spot speeds should be collected?
(b) If the estimate of the average must be within 1 mi/h, what should the sample
size be?
Please solve and explain step by step, thank you
An engineer, wishing to determine the travel time and average speed along a sectionof an urban highway as part of an annual trend analysis on traffic operations, conducteda travel time study using the floating-car technique. He carried out 10 runs andobtained a standard deviation of ±3 mi/h in the speeds obtained. If a 5% significancelevel is assumed, is the number of test runs adequate?
Chapter 4 Solutions
MindTap Engineering for Garber/Hoel's Traffic and Highway Engineering, 5th Edition, [Instant Access], 1 term (6 months)
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- Complete answerarrow_forwardAn engineer, wishing to determine the travel time and average speed along a section of an urban highway as part of an annual trend analysis on traffic operations, conducted a travel time study using the floating-car technique. He carried out 10 runs and obtained a standard deviation of ±3.4 mi/hin the speeds obtained. If a 5 percent significance level is assumed, is the number of test runs adequate?arrow_forwardQ3. The below Table shows the time and distance for 10 vehicles recorded during a traffic survey. Choose the correct answer of the following (Four only): 1. The Average Spot Speed of the sample in the Table equals: a. (68.5) Km/hr c. (19.21) Km/hr e. (18.9) Km/hr (20 Marks Time (sec) 5.0 Distance (m) b. (190.21) Km/hr d. (67.9) Km/hr f. None of them Distance/time (m/sec) 20.00 100 5.6 100 17.86 5.6 100 17.86 4.8 100 20.83 2. The Time Mean Speed (TMS) of the sample in the Table equals: a. 68.5 (Km/hr) c. 19.21 (Km/hr) e. 18.9 (Km/hr) 6.1 100 16.39 5.3 100 18.87 b. 190.21 (Km/hr) d. 67.9 (Km/hr)- f. None of them 5.9 100 16.95 5.2 100 19.23 4.5 100 22.22 5.0 100 20.00 3. The Space Mean Speed (SMS) of the sample in the Table equals: a. 68.5 (Km/hr) d. 67.9 (Km/hr) Total 53 1000 190.21 b. 190.21 (Km/hr) e. 18.9 (Km/hr) c. 19.21 (Km/hr) f. None of them 4. The Average travel Speed of the sample in the Table equals: a. 68.5 (Km/hr) d. 67.9 (Km/hr) b. 190.21 (Km/hr) e. 18.9 (Km/hr) c. 19.21…arrow_forward
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