Only look at C. The rest are correct except 88%

A firm uses a serial assembly system and needs answers to the following: a. An output of 630 units per shift ( 7.70 hours) is desired for a new processing system. The system requires product to pass through four stations where the work content at each station is 42 seconds. What is the required cycle time for such a system? (Round your answer to the nearest whole number.) b. How efficient is your system with the cycle time you calculated? (Round your answer to 1 decimal place.) c. Station 3 changes and now requires 50 seconds to complete. What will need to be done to meet demand (assume only 7.70 hours are available)? What is the efficiency of the new system? (Round your answer to 1 decimal place.)