$($d$)$ Suppose that in the next time period, the quantities of activities change to $8,500$ customer orders, $350$ customer complaints, and $500$ credit checks. Using the information and activity cost driver rates developed in part $($b$),$ determine the cost assigned to each of the activities and the estimated hours of unused capacity as well as the associated cost. Think about why the activity cost driver rates computed in part $($a$)$ are different from the rates computed in part $($b$).$