Please explain where each number comes from.

E8-11 (LO3) FIFO, LIFO and Average-Cost Determination) John Adams Company's record of transactions for the mons April was as follows. Purchases Sales April 1 (balance on hand) 600 $6.00 1,500 6.08 800 6.40 1,200 6.50 7006.60 500 6.79 500$10.00 9 1,400 10.00 600 11.00 23 1,200 11.00 27 90012.00 April 3 13 21 29 4,600 5,300 Instructions (a) Assuming that periodic inventory records are kept in units only, compute the inventory at April 30 using (1) LIFO and (2) average-cost. (b) Assuming that perpetual inventory records are kept in dollars, determine the inventory using (1) FIFO and (2) LIFO (c) Compute cost of goods sold assuming periodic inventory procedures and inventory priced at FIFO. (d) In an inflationary period, which inventory method-FIFO, LIFO, average-cost-will show the highest net income