can you please explain the math used to get the answers.. Thanks!!

Variable and Absorption Costing Whirlpool Corporation had the following abbreviated income statement for a recent year: (in millions) $18,666 Net sales..................... Cost of goods sold $16,089 Selling, administrative, and other expenses 1,621 $17,710 Total expenses Income from operations 956 Assume that there were $4,024 million fixed manufacturing costs and $930 million fixed selling, administrative, and other costs for the year. The finished goods inventories at the beginning and end of the year from the balance sheet were as follows: $2,792 million January 1 December 31 $2,354 million Assume that 30% of the beginning and ending inventory consists of fixed costs. Assume work in process and materials inventory were unchanged during the period