CE93 HW1

# CE93 HW1 - 2 Cumulative frequency diagrams of γ and f c...

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CE93-Engineering Data Analysis Joan Walker, Spring 2011 Homework 1: Graphical Representation of Data Due 2/2/2011 11:10AM (at the beginning of class) The data file “HW1data.txt” on the course website, taken from Ref. 1, lists the measured densities (in kg/m 3 ) and the 28-day compressive strengths (in N/mm 2 ) of 38 concrete cubes. Let γ denote the density and f c denote the corresponding compressive strength. (These are the conventional notations used in engineering for these quantities). Using MATLAB, prepare the following graphs for these data: 1. Histograms, frequency diagrams, normalized frequency diagrams and normalized frequency polygons for γ and f c . Try experimenting with different numbers of equal or unequal bins. Present what you think are the best results. Comment on the range, dispersion and skewness of the sample distributions.
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Unformatted text preview: 2. Cumulative frequency diagrams of γ and f c ’ . Determine the quartiles of each variable, the interquartile range, and the quantiles at 0.1 and 0.9 cumulative frequencies. 3. Box plots of γ and f c ’ . Are there any outliers in the data? Do you observe any asymmetry in the distribution of either sample? 4. Scatter plot of f c ’ versus γ. Do you think these two variables are dependent? Describe the nature of the dependence if you observe it. 5. Q-Q plot of f c ’ versus γ. Do you think these two samples have similar distributions? Please submit your homework by turning in a hard copy. Please provide adequate details in your answers. Graphs alone are not sufficient. Reference [1] Kottegoda, N.T., and R. Rosso (1997). Probability, statistics, and reliability for civil and environmental engineers . McGraw-Hill, NY, New York....
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## This note was uploaded on 06/02/2011 for the course CIV ENG 93 taught by Professor Staff during the Spring '08 term at Berkeley.

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