What type of study was conducted, and what is the response variable of the study?
Answer:
The study described indicates an observational study. In an observational study, the researchers observe and gather data without intervening or manipulating the environment. In this case, measurements of water quality were taken from different depths of the river downstream from a chemical dumpsite without any external interference.
The response variable in this study is the concentration of the certain chemical in the water samples collected at various depths: surface, mid-depth, and bottom of the water. This variable is the one being measured and observed to assess the impact of the abandoned chemical dumpsite on the water quality. The concentrations of the chemical at different depths serve as indicators of how the chemical pollutant is distributed in the water column and whether there are any noticeable trends or variations in concentration levels based on depth.