1. **State the problem:** We need to evaluate the function $$y = 5 \cdot 2^x$$ for $$x = 3$$. 2. **Formula used:** The function is given by $$y = 5 \cdot 2^x$$. 3. **Evaluate the exponent:** Calculate $$2^3$$. 4. **Calculate $$2^3$$:** $$2^3 = 2 \times 2 \times 2 = 8$$. 5. **Multiply by 5:** Now multiply 5 by 8. 6. **Final calculation:** $$y = 5 \times 8 = 40$$. 7. **Answer:** Therefore, when $$x = 3$$, $$y = 40$$.