Answer and Explanation:
The journal entries are shown below:
On Aug 6
Inventory (60 × $150) $9,000
        To Accounts Payable $9,000
(being inventory purchased on account is recorded)
On Aug 7
Inventory Dr $350
            To Cash $350
(Being freight charges paid in cash)
On Aug 10
Accounts Payable	$600 (4 × $150)  
         To Inventory $600
(Being returned inventory is recorded)
On Aug 14
Accounts Payable  ($9,000 - $600) $8,400
          To Inventory  ($8,400 × 3%) $252
          To Cash $8,148
(Being cash paid is recorded)
On Aug 23
Accounts Receivable ($170 × 40) $6,800
        To Sales revenue $6,800
(Being sales is recorded)
Cost of goods sold $6,070
     To Inventory $6,070
(Being cost is recorded)