$D=10,000$ units $($annual demand$)$

$S=$$$20$ to place each order

$i=20$ percent of cost $($annual carrying cost, storage, interest, obsolescence, etc.$)$

$C=$ Cost per unit $($according to the order size; orders of $0$ to $499$ units, $$5\mathrm{.}00$ per u $999,$$$4\mathrm{.}50$ per unit; $1,000$ and up$,$ $$3\mathrm{.}90$ per unit$)$