1. Water Sampling, testing, and statistical application<br />During the seminar on water sampling, we learned how to do a water sample and also how to analyze it using modern techniques like Idexx Colilert powder. We observed some of the samples that Dr. Javier Arce took during the past year in some of the communities that are in Cayey, specifically in the area of Guavate. We observed the results and translated the data to a number that is statistically relevant. These numbers can be: the mode, median, mean or average, standard deviation and variance. In addition, I learned how to apply the null hypothesis and alternative hypothesis to my results in the laboratory. Finally we concluded, observing the statistical numbers and graphs that show the relationship between the urban coverage area and the MPN of E. coli. In general, the urban samples of the river were more contaminated than the rural samples of the river. <br />Carlos Santos Perez<br />804-10-8280<br />University of Puerto Rico<br />Cayey P.R.<br />