Question

researchers who examined health records of thousands of males found that men who died of myocardial infarction (heart attacks)

a) is this an experiment? if not, what kind of study is it?
no, this is a retrospective study since previous conditions are determined.

b) is it correct to conclude that shorter men are at higher risk of dying from a heart attack? explain
a. no, since it cannot be determined which of the subjects will die from heart attacks in the future
b. no, since there may be confounding variables interfering with the treatment, such as patient age or weight.
c. no, since there may be lurking variables, such as patient age or weight.
d. yes, since the result is considered to be statistically significant.

Explanation:

To determine the correct answer, we analyze each option:

• Option A is incorrect because the study is about past events (men who died), not future prediction.
• Option B is incorrect as there's no "treatment" in this observational study.
• Option C is correct. In observational studies (like this retrospective one), lurking variables (e.g., age, weight) can affect the relationship between height and heart attack risk, so we can't conclude causation.
• Option D is incorrect because statistical significance alone doesn't imply causation, and lurking variables can still be present.

Answer:

C. No, since there may be lurking variables, such as patient age or weight.