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: Pearson New International 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)
- draw the particle size distribution curve for the given table using excel.arrow_forwardWhat shows the PDF for a normal distribution determined from the unconfined compres-sion tests shown in the histogram. Does the mean and standard deviation of this PDF represent aleatory or epistemic uncertainty? Explain.arrow_forwardThe value of F is based on the ratio of the standard deviations of the two independent samples that would yield?arrow_forward
- Select an appropriate transformation, transform your data and perform a least-squares regression analysis on the transformed data to find a-hat and b-hat.a) Derive the equation that gives the relationship between depth and discharge. b) Compare these results with your Log-Log graph resultsarrow_forwardA 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_forwardAn analysis of city drinking water for total hardness was done by two students in the laboratory and produced the following results (in ppm CaCO3): Student A: 228.3, 226.4, 226.9, 227.1, and 228.6. Student B: 229.5, 226.1, 230.7, 223.8, and 227.5 1] Calculate the following for each data set: a) mean b) median c) standard deviation d) coefficient of variation e) the 95% confidence interval for the meanarrow_forward
- Distinguish Sample Range from Sample Variance. Distinguish Sample Standard Deviation from Sample Mean.arrow_forwardthe allowed discrepancy for the t-test is 2σ. This means that if your result from the t-test is smaller than 2, there is a 95% probability that the two measurements represent the same quantity and therefore, they are consistent with each other.When a set of data is inconsistent, it indicates that Select one: a. The experiment is incorrect and unreliable. b. There was a calculation mistake. c. The uncertainty on the measurements has been overestimated. d. There are some unknown systematic errors in some or all of the measurements.arrow_forwardThe following data were obtained by a laboratory practice. Calculate γ and γ (sat)arrow_forward
- Find the following: 1. Find the probable error 2. Find the standard deviation. 3.Find the standard error. Find the standard error.arrow_forwardA civil engineer measures the distance of points A and B and the following values were recorded in a series of measurements. Trials (T)1 with No. of Measurements (NM)= 200.58, T 2 with NM= 200.40; T 3 with NM = 200.38 and T 4 with NM = 200.46. Determine the average value (mean), probable error of mean, and precision of the measurements..arrow_forwardComment on the accuracy of the data or results and account of any variation obtained when conducting experiments. What do you think are the factors that affect the accuracy of the result?arrow_forward
- Engineering Fundamentals: An Introduction to Engi...Civil EngineeringISBN:9781305084766Author:Saeed MoaveniPublisher:Cengage Learning