Determine whether the samples are independent or dependent.

To test the effectiveness of a drug comma cholesterol levels are measured in 90 men before and after the treatment. Choose the correct answer below.

A. The samples are dependent because there is not a natural pairing between the two samples.

B. The samples are independent because there is not a natural pairing between the two samples.

C. The samples are independent because there is a natural pairing between the two samples

D. The samples are dependent because there is a natural pairing between the two samples.

Answer: Option (D) is the correct option

Explanation:

Natural pairings defines coupling of data sets or sample is possible to take place in a particular condition naturally. These samples depend on each other for matching.

According to the question, cholesterol level of 90 men is being assessed prior and after treatment takes place. Thus, same 90 men are going through drug testing in natural pair form and showing sample dependency before and afterwards of treatment. Thus, further analysis is based upon natural paired data.

Other options are incorrect because sample in the question are not independent due to the link between them and they do persist natural pairing with each other. Thus, the correct option is option (D).