1. **State the problem:** Find the equation of the line passing through the points $(1, 13)$ and $(3, 7)$. The equation is in the form $$y = mx + b$$ where $m$ is the slope and $b$ is the y-intercept. 2. **Find the slope $m$:** Use the formula $$m = \frac{y_2 - y_1}{x_2 - x_1}$$ where $(x_1, y_1) = (1, 13)$ and $(x_2, y_2) = (3, 7)$. Calculate: $$m = \frac{7 - 13}{3 - 1} = \frac{-6}{2} = -3$$ 3. **Find the y-intercept $b$:** Use the equation $$y = mx + b$$ and substitute one point and the slope to solve for $b$. Using point $(1, 13)$: $$13 = (-3)(1) + b$$ $$13 = -3 + b$$ $$b = 13 + 3 = 16$$ 4. **Write the equation:** Substitute $m = -3$ and $b = 16$ into the line equation: $$y = -3x + 16$$ **Final answer:** The equation of the trend line is $$y = -3x + 16$$.