Something like this ?
Graph Builder(
Show Control Panel( 0 ),
Variables(
X( :Day ),
Y( :Defect1 ),
Y( :Defect2, Position( 1 ) ),
Y( :Defect3, Position( 1 ) ),
Y( :Yield, Position( 1 ), Side( "Right" ) )
),
Elements(
Line( X, Legend( 8 ), Row order( 0 ), Summary Statistic( "Mean" ) ),
Bar(
X,
Y( 1 ),
Y( 2 ),
Y( 3 ),
Legend( 6 ),
Bar Style( "Stacked" ),
Summary Statistic( "Mean" )
),
Line( X, Y( 4 ), Legend( 9 ), Row order( 0 ), Summary Statistic( "Mean" ) ),
Bar( X, Legend( 10 ), Bar Style( "Stacked" ), Summary Statistic( "Mean" ) )
),
SendToReport( Dispatch( {}, "400", LegendBox, {Position( {0, 1, 2, 3, -1} )} ) )
)