Use the table below to answer questions 11 through 13. Demand for a certain subassembly in an engine manufacturing facility in Norfolk, Virginia is 68 items per eight-hour shift or workers. The following 6 tasks are required to produce one subassembly. Task Time required (min) Predecessor tasks a 7 - b 6 a c 4 b d 3 b e 6 b,c f 8 d,e What is the line's efficiency