Moving-Average Inventory Question: Assuming that perpetual inventory records are kept in units only, the ending inventory on an average-cost basis, rounded to the nearest dollar, is

The number I came up with was 1,300 @ $3.4 = $4,420, which the closest answer to that would be D. Is the key off or did I miss a step?

Transactions for the month of June were: Purchases June 1 (balance) 800 a $3.20 2,200 @ 3.10 1,200 @ 3.30 1,800 @ 3.40 500 @ 3.50 June 2 6 9 10 18 25 Sales 600 @ $5.50 1,600 @ 5.50 1,000 @ 5.50 400 @ 6.00 1,400 @ 6.00 200 @ 6.00 18. Assuming that perpetual inventory records are kept in units only, the ending inventory on an average-cost basis, rounded to the nearest dollar, is a. $4,096. b. $4,238. C. $4,290. d. $4,322