4. Lake Corporation manufactures two products, AA and BB, from a joint process. A production run costs $20,000 and results in 500 units of AA and 2,000 units of BB. Both products must be processed past the split-off point, incurring separable costs of $5 per unit for AA and $10 per unit for BB. The market price is $25 for AA and $20 for BB.

I have the answers I just need the work shown in detail with step-by-step instructions.

Required:

a.	Allocate joint production costs to each product using the physical units method. (Ans:AA=$4,000; BB=$16,000)
b.	Allocate joint production costs to each product using the net realizable value method. (Ans: AA=$6,667; BB=$13,333)
c.	Allocate joint production costs to each product using the constant gross margin percentage method. (Ans: AA=$7,619.05; BB=$12,380.96)