Investigators are interested in learning whether working with asbestos is associated with risk of respiratory illness.

Investigators are interested in learning whether working with asbestos is associated with risk of respiratory illness. A group of asbestos workers (n=200) and those who are administrative workers (n=150) are enrolled and followed for 60 days to determine development of respiratory illness. 10% of the asbestos workers develop respiratory illness while only 0.6% of the administrative workers do. Calculate the cumulative incidence.