Question

question 9 of 10
which situation is an example of an observational study?

a. testing the effectiveness of a new hair product by allowing one group to use it and comparing results against a group that doesnt use it

b. interviewing college students to find what percentage expect a job immediately after graduation

c. collecting the cholesterol readings of a group of elderly people in a small town

d. calling a sample of registered voters before an election to find out what issues concern them most

Explanation:

An observational study involves collecting data without manipulating variables or imposing treatments on participants.

• Option A is an experiment, as it assigns a treatment (the hair product) to one group and compares it to a control group.
• Options B, D are surveys that collect self-reported information, but they do not involve observing existing characteristics without intervention.
• Option C involves collecting existing data (cholesterol readings) from a group without manipulating any variables, which fits the definition of an observational study.

Answer:

C. Collecting the cholesterol readings of a group of elderly people in a small town