Name: An epidemiologic investigation begun on January 1st, 2009 identified a population of 50 individuals amon g whom 3 were found to have the disease under study on this date. During the year of the study, 7 additional new cases were found. Among the total of 10 cases, there were 5 deaths during the year For the 10 cases, the diagram indicates the time of case recognition, periods of observation during the study, and vital status at the time of the termination of observation. A vertical bar at the start of the diagram (patients 1, 2, and 3) indicates that the start of disease had occurred before the study began. Assume that the 40 remaining individuals in the study did not become ill or die during the year of observation. 2010 2009 JFMAMJJ A SON D J 2 h 6 9 10 I- Illness Prior to studyllness Death What is the prevalence of the disease on September 15, 2009? What is the cumulative incidence of the disease during 2009? What is the person-time at risk for the disease in this study? What is the incidence density of the disease for 2009 (per 1,000)? Page