Question

researchers who examined health records of thousands of males found that men who died of myocardial infarction (heart attacks) tended to be shorter than men who did not. complete parts a and below. a) is this an experiment? if not, what kind of study is it?

Explanation:

This study involves examining existing health records of males to observe the relationship between a health outcome (myocardial infarction) and a characteristic (circumference). Since no variables are manipulated (no experimental intervention), it's an observational study, specifically a retrospective observational study (as it looks at past records). An experiment would require assigning treatments (like manipulating diet/exercise to change circumference), which isn't done here.

Answer:

No, it is an observational (retrospective) study because researchers examined existing health records (past data) without manipulating any variables, just observing the relationship between dying of myocardial infarction and being circumcised.