An observational study is done to see if eating at least two apples a week helps prevent tooth decay in children. However, the researchers are aware that children who eat apples may also drink less soda, so they measure soda consumption as well. In this example, soda consumption is an example of
A) an interacting variable.
B) an explanatory variable.
C) a response variable.
D) a confounding variable.

Question

Quizplus · Accepted Answer

Soda consumption is considered a confounding variable because it could independently affect the outcome (tooth decay) and is associated with the exposure (eating apples), potentially distorting the apparent effect of the exposure on the outcome.

An Observational Study Is Done to See If Eating at Least