1. The figure below shows a 17-month study of disease A in 11 individuals. Please refer to the figure to answer questions. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Time at risk (months) Black lines represent time at risk. Dots represent new cases of A, and arrows represent censored observations. All follow-up is assumed to be whole numbers. 1) What is the cumulative incidence (incidence proportion) ofA at 6 months? At 17 months? (12.5points) 2) What is the point prevalence ofA at the end of the study? Assume A is not fatal, cases do not die or leave the study for any other reason, and A is incurable. (12.5points) 3) Calculate the person-months at risk for the study period. (12.5points)