Cost of orange per cubic inch

$C = \dfrac{3}{\frac{1}{6}\pi(2.5^3)(12)} = \$ \frac{12}{125\pi} / \text{in}^3$

Selling price of 2-inch grade orange

$P = CV = \dfrac{12}{125\pi} \left[ \dfrac{\pi(2^3)}{6} \right]$

$P = \$0.128 \text{ per piece}$

$P = \$1.536 \, \text{ per dozen}$ *answer*