Month

Demand

Regular Production

Subcontract

$($Units$)$

$1$

January

$900$

$660$

$660$

$240$

$240$

$2$

February

$700$

$540$

$540$

$160$

$160$

$3$

March

$800$

$630$

$630$

$170$

$170$

$4$

April

$1,200$

$630$

$630$

$570$

$570$

$5$

May

$1,500$

$660$

$660$

$840$

$840$

$6$

June

$1,100$

$600$

$600$

$500$

$500$

Part $5$

The total regular production cost

$=$$

enter your response here

$.($Enter your response as a whole$$number$.)$