Alternative methods of joint cost allocation, product mix decisions. The Southern Oil Company buys crude vegetable oil. Refining this oil results in four products at the splitoff point: A, B, C, and D. Product C is fully processed by the splitoff point. Products A, B, and D can individually be further refined into Super A, Super B, and Super D. In the most recent month (December), the output at the splitoff point was as follows:

Product A, 322,400 gallons

Product B, 119,600 gallons

Product C, 52,000 gallons

Product D, 26,000 gallons

The joint costs of purchasing and processing the crude vegetable oil were $96,000. Southern had no beginning or ending inventories. Sales of product C in December were $24,000. Products A, B, and D were further refined and then sold. Data related to December are as follows:

Separable Processing Costs to Make Super Products

Revenues

Super A

$249,600

$300,000

Super B

102,400

160,000

Super D

152,000

160,000

Southern had the option of selling products A, B, and D at the split off point. This alternative would have yielded the following revenues for the December production:

Product A, $84,000

Product B, $72,000

Product D, $60,000

1. Compute the gross margin percentage for each product sold in December, using the following methods for allocating the $96,000 joint costs:

a. Sales value at split off

b. Physical measure

c. NRV

2. Could Southern have increased its December operating income by making different decisions about the further processing of products A, B, or D? Show the effect on operating income of any changes you recommend.