Dr. Chris Murray proposed a model to describe the spread of an infectious disease. His proposal: if y = f(t) is the percent of the population that is infected at time t, then the rate of change of f(t) at any time is proportional to the product of the percentage of the population that is infected and the percentage of the population that is not infected. Set up a differential equation that is satisfied by y = f(t), where a maximum of 100% of the population can be infected. (Note: Use k for the constant of proportionality.) x, k> 0 y' = [k(f(t))(100-f(t)) symbolic formatting help