$($Hint: we worked this problem in class$)$ The Dorben Company is using the work sampling technique to establish standards for its data entry clerks. The pool six clerks, each of whom works a $40-$h week. Over a four$-$week period, $1,700$ random simultaneous observations of all six clerks were made. During the study period, the clerks produced $9,001$ entries. Of the random observations, $1,225$ showed that data entry was taking place. What is the capacity for the departme of data entry clerks?

a$.960$ hours

b$.9001$ entries

c$.6$ clerks

d$.160$ hours