Others may have an easier way, but this is how I would do it
- Use Tables==>Summary to sum the measurement column(s)  for each of the X axis groups.
- Create a new column in the summary table which is the Col Cumulative Sum() of the summarized measurement column(s)
- Graph the data

Very easy to do interactively.  But here is the script that produced the above graph
names default to here(1);
dt=Open("$SAMPLE_DATA/big class.jmp");
// Summarize the data
dtSum = dt << Summary(
	Group( :age ),
	Sum( :height ),
	Freq( "None" ),
	Weight( "None" )
);
// Create the cummulative sum column
dtSum << New Column("Height Cumulative Sum", formula( Col Cumulative Sum( :Name( "Sum(height)" ) )));
// Generate the graph
dtSum << Graph Builder(
	Size( 534, 450 ),
	Show Control Panel( 0 ),
	Variables( X( :age ), Y( :Height Cumulative Sum ) ),
	Elements( Bar( X, Y, Legend( 6 ) ) )
);
 
					
				
			
			
				
	Jim