Concept explainers
Using a random number generator create a sample of four relative densities using the PDF presented in Figure 2.2. Repeat the exercise to create three different sample sets. Compute the mean and standard deviation of your sample. Compute the mean and standard deviation of each sample set. Compare the means and standard deviations of your samples with each other and with the mean and standard deviation of the original distribution. Discuss the differences among the sample sets and the original distribution, including the type of uncertainties you are dealing with. How many samples do you think are needed to reliably determine the mean and standard deviation of the relative density of this particular soil?
Figure 2.2
Histogram and the corresponding normal distribution of dry unit weight of a compacted soil at a road site in Los Alamos, New Mexico.
Learn your wayIncludes step-by-step video
Chapter 2 Solutions
Foundation Design: Principles and Practices (3rd Edition)
Additional Engineering Textbook Solutions
Elementary Surveying: An Introduction To Geomatics (15th Edition)
Elementary Surveying (14th Edition)
Structural Analysis (10th Edition)
Materials for Civil and Construction Engineers (4th Edition)
Concepts Of Programming Languages
Starting Out with Programming Logic and Design (5th Edition) (What's New in Computer Science)
- A population has a mean of u=30 and a standard deviation of sd=5. a. If 5 points were added to every score in the population, what would be the new values for the mean and standard deviation? b. If every score in the population were multiplied by 3, what would be the new values for the mean and standard deviation?arrow_forwardFor computing the variance this number is called as the value that is added or subtracted from the most probable value. O a. Error O b. Accuracy c. Probable Error d. Mistake Clear my choicearrow_forwardI need the answer as soon as possiblearrow_forward
- 4. Which of the following is a characteristic of a confidence interval? A. It is constructed using the point estimate, standardized statistic, and standard deviation O B. A higher confidence level results to a narrower interval C. A confidence interval presents a range which shows the only values a point estimate can take. D. A confidence interval of a population will always be consistent. Warrow_forwardNEED ASAP PLS!!arrow_forward7.3) instructions: Read and Analyze the sample problems given. Give a thorough analysis stating what type of situation the author dealt with, how the problem was solved, the assumptions that the author considered in solving the problem, and why where these assumptions were made. It should have 5 sentences for each problem.arrow_forward
- Measurements of the flexible strength of carbon fiber are carried out during the design of a leg prosthesis. After 15 measurements, the mean is calculated as 1725 MPa with a standard deviation of 375 MPa. Previous data on the same material shows a mean of 1740 MPa with a standard deviation of 250 MPa. Use this information to estimate mean and standard deviation of the posterior distribution of the mean. Note: round your answers to only 2 decimals. The mean value of the posterior is type your answer. MPa and the standard deviation is type your answer. MPa.arrow_forwardA certain type of thread is manufactured with a mean tensile strength of 78.3 kg and a standard deviation of 5.6 kg. How is the variance of the sample mean changed when the sample size is a. Increased from 64 to 196? b. Decreased from 784 to 49?arrow_forwardFind the standard deviation of the following data: Size of items 10 11 12 13 14 Frequency 2 7 11 15 16 1 15 10 4 [Ans.: 1.342]arrow_forward
- A population has a standard deviation of 24. What is the standard error of the sampling distribution if the sample size is 100? A. 0.24 B. 2.4 C. 0.48 D. 4.8arrow_forwardWhat is the expected error in C in the below equation if you know the random error in A=±34 mm and B=±21.4 mm? C=A+B Answer: Choose... +arrow_forwardOnly the second image please. The first one is for reference.arrow_forward
- Engineering Fundamentals: An Introduction to Engi...Civil EngineeringISBN:9781305084766Author:Saeed MoaveniPublisher:Cengage Learning