Great Ape Glassworks manufactures glass used for the screens on smartphones. It has two producing departments, P$1$ and P$2,$ and only one service department, S$1.$ The company is able to track overhead to the various departments but wants to allocate the service department costs to the producing departments. However, the company is not sure which of the multiple allocation bases should be selected. The data it collected appear in the table below.

Department Overhead Assigned

P$1$ $ $150,000$

P$2250,000$

S$174,000$

Potential allocation base P$1$ P$2$

Employee headcount $6020$

Space used $($in square feet$)2,0006,000$

Productive capacity $($in units$)50,00075,000$

$3-$year average percentage of S$1$ output used $60\%40\%$