$4.)$ Bigstone Company's Stonehenge Division manufactures small sculptures. The Miniature Division of Bigstone Company assembles and packages small sculptures and other items. Both divisions are free to buy and sell any of their components internally or externally. The following costs relate to small sculpture on a per unit basis.

Fixed cost per unit $$5$

Variable cost per unit $$9$

Selling price per unit $,$$$29$

$($a$)$ Assuming that the Sculpture Division has excess capacity, compute the minimum acceptable price for the transfer of small sculpture to the Miniature Division.

$($b$)$ Assuming that the Sculpture Division does not have excess capacity, compute the minimum acceptable price for the transfer of the small sculpture to the Miniature Division.

$($c$)$ Assuming that the Sculpture Division does not have excess capacity, compute the minimum acceptable price for the transfer of $5,000$ units special sculpture to the Miniature Division. Production of special sculpture will cause additional variable costs of $$3$ and Sculpture division will need to forgo $6,000$ units of regular small sculptures.