Please help with the red highlighted "Specific identification" & "Average cost"

Metlock SA's record of transactions concerning part X for the month of April was as follows. Compute the inventory at April 30 on each of the following bases. Assume that perpetual inventory records are kept in units only: (Round final answers to 0 decimal places, e.g. 6,548.) (1) Specific identification; ending inventory is comprised of 290 units from beginning inventory and 440 units from the April 26 purchase (2) First-in, first-out (FIFO). (3) Average-cost