**Answer:**

Differential revenue from further processing:

**= $11.80.**

**Explanation:**

a) Data and Calculations:

Cost of production of an unfinished desk = $35.65

Selling price of an unfinished desk = $64.20

Selling price of a finished desk = $76.00

Additional processing cost = $6.15

Revenue per finished desk $76.00

Revenue per unfinished desk 64.20

Differential revenue $11.80

Differential cost per desk:

Cost of unfinished desk $35.65

Additional cost for producing 6.15

Differential from further processing $41.80

Unfinished Finished Differential

Revenue $64.20 $76.00 $11.80

Cost of production (35.65) (41.80) (6.15)

Net income $28.55 $34.20 $5.65