1. What is the incremental manufacturing cost incurred if the company increases production from 29,750 to 29,751 units

$17.90  

Explanation:

The below is missing from the question:

Kubin Company’s relevant range of production is 28,000 to 31,500 units. When it produces and sells 29,750 units, its average costs per unit are as follows:

Amount per Unit

Direct materials  $8.80

Direct labor$5.80

Variable manufacturing overhead $3.30

Fixed manufacturing overhead$6.80

Fixed selling expense$5.30

Fixed administrative expense$4.30

Sales commissions$2.80

Variable administrative expense$2.30

In order to determine the incremental manufacturing cost by increasing the volume of production from  29,750 to 29,751 units, we simply compute the extra variable cost of producing one extra unit since 29,751 units are still within the relevant range of output, no extra fixed costs would be incurred.

extra cost per unit=direct materials+direct labor+Variable manufacturing overhead

Sales commissions and Variable administrative expense are not included because they are not manufacturing costs

extra cost per unit= $8.80 +$5.80 +$3.30 =$17.90