Thanks for your prompt reply.
I have followed the steps and found that the account is correct.
Please see below:-
Inv. 11451 with sales amount $38,560.00 is now tagged to cost $67,120.00 and the same goes to Inv. 11452. What should I do to map Inv. 11451's sales amount $38,560.00 to its cost of $33,560.00 instead of $67,120.00?