After a heavy storm the waste water holding tanks at a waste

After a heavy storm, the waste water holding tanks at a waste water treatment plant on the New River overflowed dumping 1,000,000 gallons of sewage into the New River. You are part of the New River Citizen Watch Group, which monitors the health of portions of the New River for government agencies like the EPA and USDA. This sewage discharge event causes your group to wonder if the event has had a negative impact on the quality of the water downstream of the waste water treatment plant. To test your group\'s idea that the sewage has negatively impacted water quality, you measure in triplicate the EPT of a site upstream of the waste water treatment plant and a site downstream of the waste water treatment plant. You calculate the mean 9% EPT of both sites and the 95% confidence intervals of both samples. Your results are shown below. Use this scenario and data to answer the following questions. 120 1000 60 Upstream site Downstream site

Solution

All the answers marked are correct.

1. Answer - Option C - Because both the site has the standard deviation of +/_ 20 for upstream and +/-30 for down stream in the graph provided above.

2. Answer - Option A - Because the mean of the both site are significantly different, The mean of upstream is around 82 and that of downstream is 42.

3. Answer - Option A - Because it is said in the question that the quality of the water is distributed both upstream and downstream.

4. Answer - Option A - The hypothesis is accepted due to the variation in the %EPT

5. Answer - Option A - The sewage discharge event has negatively impacted the quality of the water