HELP!! Fort Bragg in northern California is a small town of population 5000. Suppose the rate of growth of an epidemic in Fort Bragg is jointly proportional to the number of people infected and the number of people not infected. When 100 people are infected, the epidemic is growing at the rate of 9 people per day. (a) Find a mathematical model expressing the rate of growth of the epidemic as a function of the number of people infected. (b) How fast is the epidemic growing when 200 people are infected? (c) On your graphics calculator, determine how many people are infected when the rate of growth of the epidemic is a maximum.