Can someone please explain why the last two answers are over & under? I thought it was only over if it was negative.

Example 5-1 For our example, let's say we have Department A and Department B with overhead costs of 300,000 and $450,000, respectively. We might also use different bases for each department. In our example, we will use Direct Labor Hours for Department A and Machine Hours for Department B. Dept A Dept B Estimated MOH Estimated DLHs Estimated MHs 300,000 $450,00050 0oo 8000