please show all steps in completing this :)

Instructions Samuel Smith's company wants to establish an assembly line to manufacture its new product, the iStar phone. Samuel's goal is to produce 60 IStars per hour. Tasks, task times, and immediate predecessors are as follows: 1. What is the theoretical minimum for the number of workstations that Samuel can achieve in this assembly line? 2. Use the heuristic to balance an assembly line for the istar phone. 3. How many workstations are in your answer to (b)? 4. What is the efficiency of your answer to (b)