62. A large company wishes to install a pneumatic tube system that would enable small items to be sent between any of 10 locales, possibly by using relay. If the nonprohibitive costs (in $100) are shown in the accompanying graph model, between which sites should the tube be installed to min- imize the total cost? X 6 X5 8 7 12 X2 9 10 13 5 7 2 9 A (0 X3 7 6 X4 X 12