[flexcoders] summing an arrayCollection Column

[Todd Geist]

Hello,

Very new here.  Trying to get some of the basics.  I have datagrid that is 
populated with the following arrayColleciton


    <mx:ArrayCollection id="myAC">
        <mx:Array>
            <mx:Object city="Los Angeles" state="CA" population="3844829" />
            <mx:Object city="New York" state="NY" population="8143197" />
            <mx:Object city="Chicago" state="IL" population="2842518" />
            <mx:Object city="Philadelphia" state="PA" population="1463281" />
        </mx:Array>
    </mx:ArrayCollection>



How do I go about getting the sum of the population?

Thanks in advance for any advice.


Todd