Answer
$10.6\ in$
Work Step by Step
Step 1. Use the dimensions given in the exercise, we have the volume as $V=(2.3)(x-3.2)(x)=180.4$
Step 2. Rewrite the above equation as $2.3x^2-7.36x-180.4=0$
Step 3. Let $a=2.3, b=-7.36, c=-180.4$, use the quadratic formula to solve the equation and discard the negative answer to get $x\approx 10.6\ in$