Gavin Products uses a perpetual inventory system. For Year $1$ and Year $2,$ Gavin has the following data:

Activity Units Purchase Price

$($per unit$)$ Sale Price

$($per unit$)$

Year $1$

Beginning inventory $200$ $$9$

Purchase $1,$ Feb. $1530011$

Sale $1,$ Mar. $10320$ $$25$

Purchase $2,$ Sept. $1550012$

Sale $2,$ Nov. $355025$

Purchase $3,$ Dec. $2015013$

Year $2$

Sale $3,$ Apr. $420025$

Purchase $4,$ June $2520014$

Sale $4,$ Dec. $1815025$

Required:

$1.$ For each year, compute cost of goods sold, the cost of ending inventory, and gross margin using FIFO.