2.60 Chloroform According to the U.S. Environmental Protection Agency, chloroform, which in its gaseous form is suspected of being a cancer- causing agent, is present in small quantities in all of the 240,000 public water sources in the United States. If the mean and standard deviation of the amounts of chloroform present in the water sources are 34 and 53 micrograms per litre, respectively, describe the dis- tribution for the population of all public water sources.