The standard time for a manual material$-$handling work cycle is $2\mathrm{.}58$min per piece. The PFD allowance factor used to set the standard was $13\%.$ During a particular $8-$hour shift of interest, it is known that the worker lost a total of $53$min due to personal time, rest breaks, and delays. On that same day, the worker completed $214$ work units. Determine

$($a$)$ the number of standard hours accomplished

Standard hours in hours $H_{std}^{?}=$

$($b$)$ worker efficiency

Worker efficiency as a percentage $E_w=\%$

$($c$)$ the worker's performance level expressed as a percentage.

Time worked in minutes

Cycle time per piece in minutes $T_c=$

Normal time per piece in minutes $T_n=$

Worker's performance level as a percentage $P_w=\%$