Question

a relationship between two or more variables that is shown in an observational study is a:
a. social norm.
b. correlation.
c. coupling.
d. causal relationship.

Explanation:

• Option A: Social norms are unwritten rules of behavior in a society, not related to variable relationships in studies. Eliminate A.
• Option B: Correlation refers to a relationship (association) between two or more variables, which can be observed in observational studies (where we don't manipulate variables, just observe associations). This fits.
• Option C: Coupling is more about a connection in engineering or systems, not a standard term for variable relationships in observational studies. Eliminate C.
• Option D: Causal relationships (proving one variable causes another) usually require experimental designs (not just observational studies, as observational studies can show correlation but not causation easily). Eliminate D.

Answer:

B. correlation.