Answer: Please find explanation column for answers
Step-by-step explanation:
a)Journal To record sales of merchandise 
Date Accounts titles Debit Credit
Feb 1 Account receivable 1200 
Sales revenue 1200 
Journal To record cost of goods sold
Cost of goods sold 700 
Merchandise inventory 700 
b)Journal To record sales return  
Date Accounts titles Debit Credit
Feb 9 Sales return and allowance (1200/4) 300 
Account receivable 300 
To record cost of goods returned 
Merchandise inventory $190 
Cost of goods sold $190
c)Journal To record cash collection  
Mar 2 Cash (1200 -300) $900
Account receivable $900
d) Gross Profit percentage = Net Profit/Net sales =Net sales - cost oof goods sold/net sales
 Cost of goods sold = cost of goods sold - cost of goods retuened = 700- 190 = 510
Net profit/ net sales = 900- 510/ 900=490/900= 0.54 = 54%