I am confused with the following questions/concepts and am in dire need of assistance. I am trying to actually learn this so the more detailed the explanations, the better. Thank you for your time!

Beginning inventory, purchases, and sales for Item B901 are as follows: January 1 Inventory 70 units @ $17 48 units 9 Sale Purchase 64 units @ $20 26 units 28 Sale Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of merchandise sold on January 28 and (b) the inventory on January 31. a. Cost of merchandise sold on January 28 $ $ 454 1,200 b. Inventory on January 31 Perpetual Inventory Using Weighted Average Beginning inventory, purchases, and sales for Meta-B1 are as follows: 100 units at $400 July 1 12 Inventory Sale 70 units Purchase 120 units at $450 26 Sale 110 units a. Assuming a perpetual inventory system and using the weighted average method, determine the weighted average unit cost after the July 23 purchase. per unit b. Assuming a perpetual inventory system and using the weighted average method, determine the cost of the merchandise sold on July 26. c. Assuming a perpetual inventory system and using the weighted average method, determine the inventory on July 31. Periodic Inventory Using FIFO, LIFO, and Weighted Average Cost Methods The units of an item available for sale during the year were as follows: Jan. 1 Inventory 11 units at $50 $550 Purchase 795 Aug. 7 Dec. 11 15 units at $53 15 units at $54 Purchase 810 41 units $2,155 There are 17 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost using (a) the first-in, first-out (FIFO) method; (b) the last-in, first-out (LIFO) method; and (c) the weighted average cost method (round per unit cost to two decimal places and your final answer to the nearest whole dollar). a. First-in, first-out (FIFO) b. Last-in, first-out (LIFO) C. Weighted average cost Perpetual Inventory Using LIFB Beginning inventory, purchases, and sales for Item CZ83 are as follows: March 1 Inventory Sale 5 92 units @ $21 74 units 102 units @ $24 11 Purchase 21 Sale 86 units Assuming a perpetual inventory system and using the last-in, first-out (LIFO) method, determine (a) the cost of merchandise sold on March 21 and (b) the inventory on March 31. a. Cost of merchandise sold on March 21 b Inventory on March 31