Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 20

EPA: Wetlands Where does all the water go According to the Environmental Protection Agency (EPA), in a typical wetland environment, 38% of the water is outflow, 47% is seepage, 7% evaporates, and 8% remains as water volume in the ecosystem (Reference: U.S. Environmental Protection Agency Case Studies Report 832-R-93-005). Chloride compounds as residuals from resi­dential areas are a problem for wetlands. Suppose that in a particular wetland environment the following concentrations (mg/L) of chloride compounds were found: outflow, 64.1; seepage, 75.8; remaining; due to evaporation. 23.9: in the water volume, 68.2.
(a) Compute the weighted average of chlorine compound concentration (mg/L) for this ecological system.
(b) Suppose the EPA has established an average chlorine compound concentration target of no more than 58 mg/L. Comment on whether this wetlands system meets the target standard for chlorine compound concentration.