The Women's Health Study included 39,876 female health professionals aged 45 years and older who were followed for an average of 10 years (Ridker et al., 2005). At the beginning of the study, participants were randomly assigned to take either a daily low-dose aspirin or a daily placebo pill for the duration of the study. At the end of the study, researchers measured the number of participants that suffered from a heart attack during the study. Data are summarized in the following table.
-Is a theory-based approach appropriate to evaluate the relationship between whether an individual took aspirin or a placebo and whether an individual suffers a heart attack?

Question

The Women's Health Study included 39,876 female health professionals aged 45 years and older who were followed for an average of 10 years (Ridker et al., 2005). At the beginning of the study, participants were randomly assigned to take either a daily low-dose aspirin or a daily placebo pill for the duration of the study. At the end of the study, researchers measured the number of participants that suffered from a heart attack during the study. Data are summarized in the following table. 
-Is a theory-based approach appropriate to evaluate the relationship between whether an individual took aspirin or a placebo and whether an individual suffers a heart attack?

Quizplus · Accepted Answer

A theory-based approach is appropriate because the sample sizes (198, 193, 19,736, 19,749) are all greater than 10, satisfying the conditions for using normal approximation in hypothesis testing.

The Women's Health Study Included 39,876 Female Health Professionals Aged