a. Sold merchandise for cash (cost of merchandise $28,797). $ 51,200 b. Received merchandise returned by customers as unsatisfactory (but in perfect condition) for cash refund (original cost of merchandise $360). 600 c. Sold merchandise (costing $4,750) to a customer on account with terms n/60. 10,000 d. Collected half of the balance owed by the customer in (c). 5,000 e. Granted a partial allowance relating to credit sales the customer in (c) had not yet paid.

I guess that you need the journal entries:

a.

Dr Cash 51,200

    Cr Sales revenue 51,200

Dr COGS 28,797

    Cr Inventory 28,797

b.

Dr Sales revenue 600

    Cr Cash 600

Dr Inventory 360

    Cr COGS 360

c.

Dr Accounts receivable 10,000

    Cr Sales revenue 10,000

Dr COGS 4,750

    Cr Inventory 4,750

d.

Dr Cash 5,000

    Cr Accounts receivable 5,000

e.

Dr Sales allowances

    Cr Accounts receivable

i would say iii (3) because in order to compare a price you have to use as a reference other near stores because it's its

hope i explained myself