Answer:
The company's plantwide overhead rate is 21.19%
Step-by-step explanation:
given information:
indirect labor = $8,320,000
factory utilities = $155,500
machine hours = 400,000
to calculate the overhead rate, we can use the following formula

in this case.
the indirect cost = indirect labor + factory utilities
= $8,320,000 + $155,500
= $8,475,500
allocation measure = 400,000
thus,

= 21.19%