The question letters are:
a) Identify the variable.
b) is the variable quantitatie or qualitative?
c) What is the implied population?
Answer:
a) Nitrogen concentration
b) Quantitative
c) The entire lake
Step-by-step explanation:
The samples are studied to determine the variable, which is the physical or chemical property that indicates something about the placed studied. If the variable only indicates the presence or absence of a substance it's called qualitative, and if it gives value and determines how much of the substance is ar the sample, it's quantitative.
So, the study wants to know if the nitrogen concentration is too high, so it needs nitrogen concentration as a variable. The variable will give the amount of nitrogen, thus it's quantitative. The samples were got in the lake, so, the implied population by the study is the entire lake.