Now the question is: Are 窶弃roduction cost窶 and 窶彜elling price窶 independent? Not if they are influenced by some common uncertain factor. The main contributor to the production cost and the selling price is the number of chocolate bars produced and sold. Assuming that we are able to adjust the production to the demand, we can represent this quantity by a single node which we will call 窶廸umber of chocolate bars窶.
Create a new node by clicking on the 窶廬ndependent窶 button in the toolbar.
Name the new node 窶廸umber of chocolate bars窶, either by editing the name field in the dialog box, or by activating the title field. (Most likely you will find the latter method a little bit more convenient.)
