Suppose the rate at which a rumor spreads - That is, the number of people who have heard the rumor of over a period of time - Increases with the number of people who have heard it. If Y is the number of people who have heard the rumor, the following function, where t is the time in days, is true. dy/dt = ky b) use the value k~ 0.5 to find y for t = 4