1) The following data is related to an unusual episode when the SS Titanic sank in the early twentieth century.

Explain the epidemiological attributes of this episode.

2) In which special circumstances can cross-sectional surveys be utilized to test the hypotheses? In your answer explain briefly the characteristics of the cross-sectional study.

3) Case-control studies can be of a higher quality rather than a prospective cohort study. Describe why you agree or disagree with this statement.