Answer:
a. $6,763.40 
Step-by-step explanation:
The computation of the selling price is shown below:
But before that the predetermined overhead rate is 
For machining 
= ($102000 ÷ 17,000) + $1.70 
= $7.7 per machine hour 
 For fabrication 
= ($61200 ÷ 6000) + $4.10 
= $14.30 per labour hour 
 Now the selling price is 
Direct material ($720 + $380) $1,100 
Direct labor ($900 + $1,500) $2,400 
Machining department overhead (7.7 × 80) $616 
Fabrication department overhead (50 × 14.3) $715 
Total manufacturing cost $4,831 
Markup 40% $1,932.40 
Selling price $6,763.40