Suppose you are the new supply manager at FedEx. You need to choose three hubs for the company. Each of 28 cities will send all of its outgoing packages to one of the hubs. The packages will then be sent from the hubs to their final destinations. The excel  file lists the distances between cities and the number of packages to be sent from each city to each other city. Each hub, regardless of its location, can handle at most 1600 packages. Where should the hubs be located (they must be located in three of the 29 cities), and which cities should be assigned to which hubs, to minimize the total distance the shipments travel?