Help with part b)

*E5.15 (LO) AP On January 1, 2021, Casselberry Retailers had inventory of $50,000. On December 31, 2021, total inventory on hand was $66,000. Casselberry reported the following account balances on December 31: Calculate various income statement items-periodic system and earnings approach. Freight in $ 4,000 Purchases 509,000 Purchase returns and allowances 2,000 Purchase discounts 6,000 Sales 840,000 Sales discounts 5.000 Sales returns and allowances 10,000 Instructions a. Calculate Casselberry Retailers' 2021 gross profit. b. Calculate Casselberry Retailers' 2021 operating expenses if profit is $130.000 and there are no non-operating activities