1. The problem states that the rodent population is 380 and grows at 4% per year. 2. The formula for exponential growth is $$y = y_0 (1 + r)^t$$ where $y_0$ is the initial population, $r$ is the growth rate, and $t$ is time in years. 3. Here, $y_0 = 380$ and $r = 0.04$. 4. Substitute values into the formula: $$y = 380 (1 + 0.04)^t = 380 (1.04)^t$$ 5. This function models the population after $t$ years with continuous growth at 4% annually. Final answer: $$y = 380 (1.04)^t$$