Question

determine whether the study is an experiment or an observational study, and then identify a major problem with the study. a medical researcher tested for a difference in systolic blood - pressure levels between male and female students who are 12 years of age. she randomly selected four males and four females for her study. this is an blank because the researcher blank the individuals. what is a major problem with the study? a. this is a convenience sample with voluntary response, which has a high chance of leading to bias. b. there is no blinding, which has a high chance of leading to bias. c. the sample includes male and female students. d. the sample is too small.

Explanation:

An observational study just observes and measures characteristics without trying to influence the subjects. Here, the researcher is just measuring blood - pressure levels without manipulating the individuals. A major problem with a sample of only 4 males and 4 females is that it is too small to accurately represent the population of 12 - year - old male and female students.

Answer:

This is an observational study because the researcher did not interfere with the individuals.
D. The sample is too small