Why is that reasonable? Well, the larger the population, the larger the rate at any given time. If you have a thousand people, the rate at which they're reproducing is going to be more, or a thousand insects, is going to be more insects per second or per day or per year than if you only have 10 insects. So it makes sense that the rate of growth of your population with respect to time is going to be proportional to your population. And so, you know, sometimes you think of differential equations as these daunting, complex things, but notice, we've just been able to express a reasonably not-so-complicated idea. The rate of change of population is going to be proportional to the population. And now, once we've expressed that, we can actually try to solve this differential equation, find a general solution, and then we can try to put some initial conditions on there or some states of the population that we know to actually solve for the constants to find a particular solution.