What is the unit cost per tire when 4,000 tires are produced?

$76

Explanation:

If Blue Wagon sells everything it produces, this means that the capacity of the factory is underutilised and so more goods can be produced.

The fixed cost for producing 3,000 tires will therefore be the fixed costs for producing 4,000 tires.

= 20 * 3,000

= $60,000

Total cost when 4,000 tires are produced is;

= Variable costs + fixed costs

= (38 * 4,000) + ( 14 * 4,000) + ( 9 * 4,000) + 60,000

= 152,000 + 56,000 + 36,000 + 60,000

= $304,000

Cost per tire;

= 304,000/4,000

= $76