At a local health club, a researcher samples 75 people whose primary exercise is cardiovascular and 75 people whose primary exercise is strength training. The researchers objective is to assess the effect of type of exercise on cholesterol. Each subject reported to a clinic to have his or her cholesterol measured. The subjects were unaware of the purpose of the study, and the technician measuring the cholesterol was not aware of the subjects' type of exercise. This is
A. an observational study
B. an experiment, but not a double-blind experiment.
C. a double-blind experiment.
D. a matched pairs experiment.

Step-by-step explanation:

The researcher randomly makes observation on two groups of 75 people each. He did not interfere with the activity but just assigned the conditions without tampering its effect.  Later on he observes and records the effects of each condition on the subjects .Thus, it is a observational study.

The experiment is not a double blinded experiment or a matched pair experiment because the researcher is aware of the conditions applied to the specific subject and their is no pair of subjects made who could be compared for the two conditions.

pay attention in your classes and concentrate the best thing you can do to raise your test scores is to pay attention when you're supposed to be learning the material: in class!

take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.