Can you provide an explanation on how to fill in the missing blanks .

Two or more items are omitted in each of the foll owing ta bul *ions of income statement data. Fill in the amounts that are missing. 2019 Sales revenue Sales returns and allowances Net sales Beginning inventory Ending i wentory Purchases Purchase returns and allowances Freight-in Cost of goods sold Gross profit on sales eTextbook and Media $291,470 $ (12,020) 279450 20,170 (5,380) 7.60 (235,420) 44,030 2020 (13,730) 349,128 31,790 261,480 (7,610) 8,490 91,650 2021 $412,630 296,509 (10,470) 12,070 (292,689) 98Z30