The continuous timing method is used to direct time study a manual task cycle consisting of four elements: a$,$ b$,$ c$,$ and d$.$ Two parts are produced each cycle. Element d is an irregular element performed once every six cycles. All elements were performance rated at $80\%.$ The PDF allowance is $12\%.$ Determine $($a$)$ the normalized time for the cycle, $($b$)$ the standard time per part, $($c$)$ the worker$$s efficiency if the worker completes $844$ parts in an $8-$hour shift during which she works $7$ hours and $10$ min.