On the next page is a table of the age-specific incidence rates (per 100,000 person-years) for cancer among Black males in the United States, based on data for 2009-2013. Using these data and assuming no competing risks and constant incidence rates, calculate the 40-year risk of cancer for a 30-year old Black man.

4) In a cohort study of children under three years of age attending several day-care centers in Denmark (Auranen et al, 2009), the incidence rate of pneumococcal infections was reported to be 247.1/100 child-years during the study period from 1999 to 2001. The average duration of a pneumococcal infection was estimated to be 25 days. Assuming steady-state conditions, calculate the prevalence of a pneumococcal infection in these children.