Question

Recently, a report in the Centers for Disease Control (CDC) publication Morbidity and Mortality Weekly described a string of individual cases of Norwalk virus gastroenteritis occurring on cruise ships. A concerned cruise ship owner contacted you to conduct a cross-sectional study on board his ship. You interviewed all of the passengers the cruise ship (N=3,000) and obtained the following information on the passenger’s recreational activities.

	Developed gastroenteritis	Did not develop gastroenteritis	Total
Ever swam in pool	100	900	1,000
Never swam in pool	100	1,900	2,000
Total	200	2,800	3,000

C. Calculate the prevalence difference between those exposed to swimming and those not exposed to swimming. Interpret your answer in ONE SENTENCE.  Show your work to receive full points. (1 Point)

Answer 1

For checking whether there is difference between those who exposed to swimming and those who didn't, we can use chi-square testing for checking equality.

Conclusion :

there may be prevalence difference between those who exposed to swimming and this who didn't

This means, the report of CDC may be correct.