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# Analyzing water sample data with minitab

I have several questions about water samples that I am having difficulty with. Please utilize minitab to complete work.

1. Fifty samples of water effluent from a chemical processing facility were measured for a required EPA report. The ppm of suspended solids in each specimen is presented in the following table. (a) Examine descriptive statistics of the mean, median, standard deviation, first quartile, third quartile, minimum value, and maximum value. What do these statistics indicate about the shape of the population distribution? (b) Create a histogram with binning center points at 25, 35, 45, 55, 65, 75, 85, and 95. What does the shape of the histogram tell of about the shape of the population distribution? (c) Construct a normal probability plot, a lognormal probability plot, and a Weibull probability plot of these data. Allow Minitab to estimate the best fit parameters for each distribution. Based on the plots and associated Anderson-Darling (AD) fit statistics, identify which distribution seems to be the best fit model at α = 0.05 for suspended solid material (ppm) in water.

55.8 60.9 37.0 98.6 55.8
42.3 33.8 60.6 76.0 69.0
45.9 39.1 65.5 56.0 44.6
71.7 41.2 55.5 47.2 74.5
83.2 40.0 51.7 36.7 42.3
47.3 67.6 36.3 30.0 48.2
75.3 71.4 65.2 52.6 58.2
48.0 51.8 78.8 39.8 65.0.