Answer:
The COGS for the June 1st sale is $17 per unit, and the COGS for the August 27th sale is $20 per unit.
Explanation:
Date Number of units Unit balance Unit cost Average cost
May 7 40 40 $17 $17
June 1 (20) 20 $17
July 28 30 50 $22 $20
August 27 (30) 20 $20
The average COGS after the purchase on July 28 = [(20 x $17) + (30 x $22)] / 50 = ($340 + $660) / 50 = $20