Make a New Column next to your Column of Numbers and add this Formula (:weight) is unique Column name.
Col Sum(:weight)
The other is to Launch Graph Builder with a Script
xx=colsum(:weight);
Graph Builder(
Size( 524, 492 ),
Show Control Panel( 0 ),
Variables( X( :weight ), Y( :height ), Group X( :age ) ),
Elements( Points( X, Y, Legend( 25 ) ), Smoother( X, Y, Legend( 26 ) ) ),
SendToReport(
Dispatch(
{},
"Graph Builder",
OutlineBox,
{Set Title( "Sum of Weight: "||char(xx) ), Image Export Display( Normal )}
),
Dispatch( {}, "graph title", TextEditBox, {Set Text( "Sum of Weight: "||char(xx) )} )
)
)