Answer:
$400,000
Step-by-step explanation:
total variable manufacturing overhead = sum of total machine hours required during the year x variable manufacturing overhead rate per machine hour
= (35,000 hours + 20,000 hours + 15,000 hours + 30,000 hours) x $4 per machine hour = 100,000 machine hours x $4 per machine hour = $400,000
total fixed manufacturing overhead = $50,000 per quarter x 4 quarters = $200,000