Hello Could some please help me to understand

Problem 5-8A Magna International Inc. is a leading global supplier of technologically advanced automotive components, systems, and modules. Selected financial information (dollars in US millions) follows: 2014 2013 2012 Sales $36,641 $34,835 $30,837 Cost of goods sold 31,623 30,287 27,019 Profit 1,882 1,561 1,433 Current assets 10,007 9,923 9,135 Current liabilities 7,611 7,309 6,684 (a) Calculate the gross profit margin, profit margin, and current ratio for each year. (Round Gross profit margin to 1 decimal place, e.g. 52.7 and all other answers to 2 decimal places, e.g. 52.75.) 2014 2013 2012 Gross profit margin Profit margin Current ratio : 1Concord Warehouse distributes suitcases to retail stores and extends credit terms of n/30 to all of its customers. Concord Warehouse uses a periodic inventory system and at the end of June its inventory consisted of 28 suitcases purchased at $42 each. During the month of July, the following merchandising transactions occurred: July 1 Purchased 50 suitcases on account for $42 each from Trunk Manufacturers, terms n/30, FOB destination. 2 The correct company paid $130 freight on the July 1 purchase. 4 Received $210 credit for five suitcases returned to Trunk Manufacturers because they were damaged. 10 Sold 45 suitcases that cost $42 each to Satchel World for $55 each on account. 12 Issued a $275 credit for five suitcases returned by Satchel World because they were the wrong colour. The suitcases were returned to inventory. 15 Purchased 60 additional suitcases from Trunk Manufacturers for $32.50 each, terms n/30, FOB shipping point. 18 The company paid $165 freight on the July 15 purchase. 21 Sold 54 suitcases that cost $30 each to Fly-By-Night for $55 each on account. 23 Gave Fly-By-Night a $110 credit for two returned suitcases. The suitcases had been damaged and were sent to the recyclers. 30 Paid Trunk Manufacturers for the July 1 purchase. 31 Received balance owing from Satchel World. Record the July transactions for Concord Warehouse. (Credit account titles are automatically indented when the amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter 0 for the amounts. Record journal entries in the order presented in the problem.) Date Account Titles and Explanation Debit Credit