Final answer:
To find the values of x for which the volume is greater than 230 in³, we need to solve a cubic inequality. The values of x lie within the interval (4.526, 6.242).
Step-by-step explanation:
To find the values of x for which the volume is greater than 230 in³, we need to set up an equation for the volume and solve for x.
The volume of the box is given by V = x(12-2x)(20-2x). We can simplify this equation to V = 4x³ - 64x² + 240x. Setting V greater than 230, we have 4x³ - 64x² + 240x > 230.
Solving this cubic inequality, we find that x lies within the interval (4.526, 6.242).