I need help with the lst part of the problem. and please explain how did you get the numbers. thank you

A Record transactions and prepare a partial Income statement using a perpetual inventory system (L02, 5) [The following information applies to the questions displayed below.] At the beginning of July. CD City has a balance in inventory of $3.200. The following transactions occur during the month of July. July 3 Purchase CDs on account from Wholesale Music for $2.100. terms 1/10. n/30. July 4 Pay freight charges related to the July 3 purchase from Wholesale Music. $100. July 9 Return incorrectly ordered CDs to Wholesale Music and receive credit. $200. July 11 Pay Wholesale Music in full. July 12 Sell CDs to customers on account. $5.400. that had a cost of $2,800 July 15 Receive full payment from customers related to the sale on July 12. July 18 Purchase CDs on account from Music Supply for $2.900. terms 1/10. n/30. July 22 Sell CDs to customers for cash. $4,000. that had a cost of $2,300 July 28 Return CDs to Music Supply and receive credit of $260 July 30 Pay Music Supply in full. Prepare the top section of the multiple-step income statement through gross profit for the month of July