$($d$)$ Work sampling studies for an operation were conducted for $24$ working days at a

factory. A total of $45$ observations were made during the $8$ hours working period

for each day. The number of units managed to be produced are $2,000$ units for a

month. The company operates $24$ days per month has a single $8$ hours shift per

day. The recorded observations are shown in Table Q$1\mathrm{.}1.$

Table Q$1\mathrm{.}1$

$($i$)$ Identify the total assembly standard time in minutes$/$unit$.$ Given, worker's

rating is $120\%$ and the company's allowable allowance is $20\%.$

$(2$ marks$)$

$($ii$)$ If only $12$ workers are available for over time and the overtime pay rate is

$1\mathrm{.}5$ times of the normal wage, determine the overtime cost per day for

each worker to produce $2,500$ units per month. Given, worker's salary is

RM$1,500$ per month.

$(7$ marks$)$