One model for the way diseases spread assumes that the rate at which the number of infected pe0p1e changes is proportional to the number of people infected. The more infected people there are, the faster the disease will spread. The fewer there are, the slower it will spread. Suppose that there are 10,000 cases of some infectious disease today and that in the course of any given year, the number of cases of a disease is reduced by 20%. At what rate is the number of cases changing when there are 5000 infected people (to the nearest whole number)