Answer:
$656.40
Step-by-step explanation:
The average perpetual inventory system is one in which the carrying amount of the closing balance is determined by the unit price of every purchase.
As items are purchased/sold out, the closing balance is adjusted with the movement reflected in the account balance.
Average price of purchases per unit
= (28 × $21 + 22 × $23) / (28 +22)
= $1094/50
= $21.88
Since 30 units were sold, cost of goods sold
= $21.88 × 30
= $656.40