Problem 33. 33. Abuilding contractor is designing the ductwork for the heating and air conditioning system in a new, single-story medical building. Figure 5.45 summarizes the possible connections between the primary air handling unit (node 1) and the various air outlets to be placed in the building (nodes 2 through 9). The arcs in the network represent possible ductwork connections, and the values on the arcs represent the feet of ductwork required. Starting at node 1, use the minimal spanning tree algorithm to determine how much ductwork should be installed to provide air access to each vent while requiring the least amount of ductwork