Answer the following:

1. The ______________________________ that we reviewed in week 3 is a special case of this minimal cost flow model.
2. We want to know how many units should be shipped by railroad and how many by truck. Define the Optimization problem discussed: _____________________________________________________________?
3. Minimum cost flow is based on __________ and __________.
4. The network consists of nodes. How is a node shown in this example? ____________________________________. These are the circles on the flow.
5. How is an arc, the connections between the nodes, shown in this example? ______________________________. These are the connections between the nodes.
6. Each arc has __________ and __________ limitations.
7. The factories are __________ nodes (where there is a net amount of supply generated) and the warehouses are _________ nodes (where a negative amount of demand is created).
8. The typical function of a distribution center is to __________________________________________________________________________________________. They do not create or consume capacity.
9. What does the transshipment node indicate? __________________________________________________________________________________________.
10. Define the conservation of flow for a distribution center: ___________________________________________________________________________________________.
11. Capacity is the same as the ______________________________; at least one node must be a supply node. If your not a supply node or a demand node, it is a transshipment node.
12. Flowing units across an arc is a _______________. The units shipped across the arc times the cost per unit to ship across the arc. Its a proportionality.
13. The ____________________ is determined by the fact that the sum of the supply is equal to the sum of the demands.
14. In the spreadsheet model, the _______________ are the flow amounts. These can be changing cells along the arcs.
15. In the spreadsheet model, the supply / demand column is _________________________, listed as supply or demand. .
16. In the spreadsheet model, the total cost is the sum of
    1. How much you are __________ on each arc of the network.
    2. Multiplied by the __________ to ship along that arc
17. From the optimization perspective, we are trying to _______________________.
18. A constraint is that we must meet the _____ flow. There are also arc constraints for the amount that can be trucked. Non-negativity is also a constraint.
19. Net flow is the sum off all the flow out of a node _______ the flow into a node.
20. How does the excel formula SUMIF WORK?
21. The MS Excel add-on you can use to solve this minimal cost network flow problem is called __________.