1. **State the problem:** We are given the exponential function $$y = 300 \left(\frac{1}{2}\right)^{-\frac{x}{68}}$$ and need to understand its behavior. 2. **Formula and explanation:** The general form of exponential growth/decay is $$y = a b^{x}$$ where $a$ is the initial amount and $b$ is the base. - If $0 < b < 1$ and the exponent is positive, the function represents exponential decay. - If $b > 1$ or if the exponent is negative with $0 < b < 1$, the function represents exponential growth. 3. **Rewrite the function:** Since the exponent is negative, rewrite the function to see the growth clearly: $$y = 300 \left(\frac{1}{2}\right)^{-\frac{x}{68}} = 300 \left(2\right)^{\frac{x}{68}}$$ 4. **Interpretation:** The base is now $2^{\frac{1}{68}} > 1$, so the function represents exponential growth. 5. **Summary:** The function starts at $y=300$ when $x=0$ and grows exponentially as $x$ increases, doubling every 68 units of $x$. **Final answer:** The function $$y = 300 \left(\frac{1}{2}\right)^{-\frac{x}{68}}$$ represents exponential growth with doubling time 68.