EXAMPLE 2: Example 2. Figure 1 below represents episodes of an illness in a population of 50 over a period O of 12 months. Each horizontal line represents the period of time one person spends being ill. The down arrow indicates the date of onset, the up arrow the date of recovery and the plus sign shows the date of death. Figure 1 + 0 、 10/1/1990 + 0 . ⇧ 。 ⇧ . ⇧ 合 4/1/1991 9/30/1991 Question 5: For Example 2, Figure 1 calculate the Point Prevalence per 100 on April 1, 1991. Question 6: For Example 2, Figure 1 calculate the Period Prevalence per 100 from October 1, 1990 to April 1, 1991. Question 7: For Example 2, Figure 1 calculate the Incidence Risk per 100 from April 1, 1991 to September 30, 1991