Vindor Incorporated can purchase component $J$ from $3$ potential suppliers. Supplier A charges a fee of $$6\mathrm{.}25$ per component. Supplier B charges $$1400$ per order plus $$2\mathrm{.}00$ per component ordered. Supplier C charges $$4\mathrm{.}00$ per component, and requires the buyer to pay for at least $300$ components $($even if the order size is less than $300)$

$4.$ What is the full range of order sizes where each supplier is optimal?

$5.$ Vindor decided to buy $400$ units of component $J$ from supplier B$.$ How much money could the company have saved if it purchased the $400$ units from supplier $C$ instead of supplier B$?$

$6.$ Next week supplier B will be running a $12\%$ off special. What equation represents the new Total Cost for supplier B during the sale?

The new equation should provide a cost that is $12\%$ less than the original