A new back-up power generator is to be located to serve a total of six precision machines in a manufacturing facility. Separate electrical cables are to be run from the generator to each machine. The locations of the six machines are P1  (0, 0), P2  (30, 90), P3  (60, 20), P4  (20, 80), P5  (70, 70), and P6  (90, 40). Determine the location for the generator that will minimize the total required length of the electrical cable.

Assume rectilinear distance.