im having a hard with this problem can you help me please!

Problem Set 1 A series of iPhones have been perceived as a genuine American product since its design and engineering are created out of the ingenuity and skill of engineers, industrial designers, and software developers in Cupertino, California. Interestingly, since its inception in 2007, Apple has been a game changer in mobile phone industry by creating a smartphone ecosystem in which specialized materials, parts and systems-printed circuit board (PCB), metal casings, memory chip, the modem, the camera module, the microphone and the touch-screen controller-are sourced from over 200 suppliers in Switzerland, Mongolia, China, Korea, Japan, and Taiwan. Hundreds of thousands of iPhones are manufactured in Chinese factories every day. One production line in a Foxconn factory located in the central Chinese city of Zhengzhou can assemble 3,600 iPhones per day. This assembly line will operate 1,200 minutes per day. The following table contains information on an iPhone's task times and precedence relationships: TASK TASK TIME (SECONDS) IMMEDIATE PREDECESSOR A: Assemble cover and prepare base assembly B: Install OLED in cover C: Install CPU and memory D: Install speaker and microphone E: Install battery pack F: Final assembly G: Start software load H: Testing and Packaging C. DE a. Establish the tasks' relationship diagram b. What is the workstation cycle time required to produce 3,600 iPhone units per day? TASK TIME (SECONDS) IMMEDIATE PREDECESSOR TASK A: Assemble cover and prepare base assembly B: Install OLED in cover C: Install CPU and memory D: Install speaker and microphone E: Install battery pack F: Final assembly G: Start software load H: Testing and Packaging C, D, E F G a. Establish the tasks' relationship diagram b. What is the workstation cycle time required to produce 3,600 iPhone units per day? c. Balance this line using the largest number of following tasks. Use the longest task time as a secondary criterion. How many workstations does it require for this assembly line? d. What is the efficiency of your line balance assuming it is running at the cycle time 17 from part (b)? (Round up your answer to one decimal places.)