1. **State the problem:** We have a regression equation $$\hat{y} = b_0 + b_1 x$$ where $$b_0=700$$ (y-intercept) and $$b_1=-50$$ (slope). We need to find the predicted value of $$\hat{y}$$ when $$x=3$$. 2. **Substitute the values:** Plug in $$b_0=700$$, $$b_1=-50$$, and $$x=3$$ into the regression equation: $$\hat{y} = 700 + (-50) \times 3$$ 3. **Calculate:** $$\hat{y} = 700 - 150 = 550$$ 4. **Conclusion:** The predicted value $$\hat{y}$$ when $$x=3$$ is 550. So, the correct answer is Option B: 550.