Answer:
Total Per Unit
Materials $155,200 $96
Direct labor $57,600 $48
Other costs varying with output $34,800 $29
<u>Fixed costs $540,000 $450 </u>
Total costs $747,600 $623
Since South is going to increase its production by 300 more units to be able to sell them to North, that would change the average fixed cost per unit = $540,000 / 1,500 units = $360 per unit.
Therefore the total cost per unit = $96 + $48 + $29 + $360 = $533 (instead of $623).
Since South charges its sales to North a 20% margin, the selling price per unit should = $533 x 120% = $639.60 and the total invoice for the 300 units = $639.60 per unit x 300 units = $191,880