Question

Where does all the water go? According to the Environmental Protection Agency (EPA), in a typical wetland environment, 40% of the water is outflow; 45% is seepage; 5% evaporates; and 10% remains as water volume in the ecosystem (Reference: United States 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, 72.3; seepage, 74.0; remaining due to evaporation, 65.5; in the water volume, 34.9. (a) Compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (Round your answer to one decimal place.) mg/l (b) Suppose the EPA has established an average chlorine compound concentration target of no more than 58 mg/l. Does this wetlands system meet the target standard for chlorine compound concentration? Yes. The average chlorine compound concentration (mg/l) is too high. Yes. The average chlorine compound concentration (mg/l) is lower than the target. No. The average chlorine compound concentration (mg/l) is lower than the target. No. The average chlorine compound concentration (mg/l) is too high.

Answer 1

(A) Weighted average = Sum of all weights multiplied with their data values or

using the data given in the question, we get

= (0.40*72.3) + (0.45*74) + (0.05*65.5) + (0.10*34.9)

= 28.92 + 33.3 + 3.275 +3.49

= 68.985

= 69.0 mg/l (rounded to one decimal place)

(B) Chlorine maximum value is 58 mg/l, but the weighted average calculated above in part (A) is too high as compared to 58.

Therefore, we can say that this wetlands system does not meet the target standard for chlorine compound concentration as the average chlorine compound concentration (mg/l) is too high.

option D is correct

No. The average chlorine compound concentration (mg/l) is too high.