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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.
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