Question $1[16$ points$]$

Southgate Inc. made purchases of a particular product in the current year as follows :

Ending inventory consists of $730$ units, specifically identified as follows :

$120$ units from beginning inventory

$210$ units from the February $12$ purchase

$400$ units from the July $20$ purchase

Assuming a periodic system, determine the costs to be assigned to cost of goods sold and ending inventory using the following systems :

a$.$ FIFO

b$.$ LIFO

c$.$ Weighted Average

d$.$ Specific Identification.