Watson Industries uses flexible budgets. At normal capacity of 18,000 units, budgeted manufacturing overhead is $128,000 variable and $360,000 fixed. If Watson had actual overhead costs of $500,000 for 18,000 units produced, what is the difference between actual and budgeted costs?

$16,000 favorable

$12,000 unfavorable

$4,000 unfavorable

$4,000 favorable