Environmental Engineering An article in the Journal of the Environmental Engineering Division ("Distribution of Toxic Substances in Rivers," Vol 108, 1982 pp.639-649) describes a study of the concentration of several hydrophobic organic substances in the Wolf River in Tennessee. Measurements of hexachlorobenzene (HCB) in nanograms per liter were taken at different depths downstream of an abandoned dump site. Data for two depths are as follows: Surface: 3.74, 4.61, 4.00, 4.67, 4.87, 5.12, 4.52, 5.29, 5.74, 5.48, 5.10, 4.95 Bottom: 5.44, 6.88, 5.37, 5.44, 5.03, 6.48, 3.89, 5.85, 6.85, 7.16, 5.70, 4.503. What constitutes the population of this study? What is the sample size? The sample size is 24. The number of hexachlorobenzene in nanograms per liter, both at the surface and bottom of the river, constitutes the population. 4. Compute the mean, median, and standard deviation of each data set. Surface - Mean: 4.84 Median: 4.91 Standard Deviation: 0.33 Bottom - Mean: 5.72 Median: 5.57 Standard Deviation: 0.99c) Compute the test value, z or t. If you are using the p-value method, then compute the test value and include the p-value of the test (4 decimal places). d) Make the decision to Reject Ho or Do not reject Ho. e) State your complete conclusion in the context of the claim. 8. Discuss how this information and data might be used in the real world