13.21 For a certain repetitive task, the snapback timing method was used to obtain the average work element times and performance ratings listed in the table below. Elements a, b, and care worker-controlled. Element d is a machine-controlled element and its time is the same each cycle (N.A. means performance rating is not applicable). Element c is performed while the machine is performing its cycle (element d). Element e is a worker-controlled irregu lar element performed every six cycles. The machine is idle during elements a, b, and e. One part is produced each cycle. The machine allowance is 15%, and a 15% PFD allowance is applied to the manual portion of the cycle. Determine (a) the normal time and (b) the stan- dard time for this cycle. If the worker's performance during actual production is 130% on all manual elements for 7.3 actual hours worked on an 8-hour shift, (c) how many units will be produced and (d) what is the worker's efficiency? Work Element a b C d Observed time (min) 0.47 0.58 0.70 0.75 2.10 Performance rating (%) 90 80 110 N.A. 85