Answer and Explanation:
The computation is shown below:
a. The underapplied or overapplied overhead is 
But before that the applied overhead is 
Applied overhead = 12400 × 19.1
= $236,840 
Now Underapplied overhead is 
= $245,000 - $236,840 
= $8,160 
2 The gross margin of the company would be decreased by $8,160