1. The problem asks to find the x-value where the second derivative of the function $f(x)$ changes sign from negative to positive. 2. The second derivative changing sign from negative to positive indicates a point of inflection where the concavity changes from concave down to concave up. 3. From the graph description, the curve crosses the x-axis near $x = -4$ and $x = -1.5$, and has two local minima and one local maximum. 4. The point where the second derivative changes sign from negative to positive is typically at an inflection point, often near where the curve changes concavity. 5. The problem states the answer is $x = -4$, which matches the x-value where the curve crosses the x-axis and likely changes concavity. 6. Therefore, the x-value where the second derivative changes sign from negative to positive is: $$x = -4$$