1. **State the problem:** We are given two points on a line representing temperature $T$ in an oven at times $t$ minutes: $(4, 390)$ and $(16, 210)$. We need to find the slope of the line between these points and interpret its meaning. 2. **Formula for slope:** The slope $m$ between two points $(t_1, T_1)$ and $(t_2, T_2)$ is given by: $$m = \frac{T_2 - T_1}{t_2 - t_1}$$ This formula calculates the rate of change of temperature with respect to time. 3. **Calculate the slope:** $$m = \frac{210 - 390}{16 - 4} = \frac{-180}{12} = -15$$ 4. **Interpretation:** The slope $-15$ means the temperature decreases by 15 degrees Fahrenheit every minute after the oven is turned off. 5. **Final sentence:** The temperature in the oven is decreasing at a rate of 15 degrees Fahrenheit per minute.