During a seminar on water sampling, students learned how to collect and analyze water samples using modern techniques like Idexx Colilert powder. They observed samples collected in communities near Cayey and analyzed the results statistically, calculating values like the mode, median, mean, standard deviation, and variance. Students also learned to apply the null and alternative hypotheses to their lab results. In conclusion, by observing statistical numbers and graphs, they determined urban river samples tended to have higher E. coli contamination than rural river samples.