Given the following summary table from a Transportation Method Production Plan:

$\backslash$table$[[$Quarter$,$Demand,Strategy Variable$],[$Regular Prod.,Overtime,Subcontract,Ending Inventory,$],[1,8,900,10,000,0,0,7,100],[2,19,800,10,000,3,000,6,300,$A$],[3,21,300,10,000,3,000,8,500,],[4,28,300,10,000,3,000,8,500,]]$

What is the value of $A($inventory at the end of the $2^{nd}$ quarter$)?$

Note: this table not related to other questions