Method of apportioning joint cost over joint products

Proper apportionment of
joint cost over the Joint Products is of considerable importance, as this affects (a)
Valuation of closing inventory; (b) Pricing of products; and (c) Profit or loss on the sale of
different products.
The commonly used methods for apportioning total process costs upto the point of separation
over the joint products are as follows :
(i) Physical unit method
(ii) Average unit cost method
(iii) Survey method
(iv) Contribution margin method