Kirtland Corporation's accounting records showed the following at December $31$:

Transactions Units Unit Cost

Beginning inventory, January $1370$ $$4\mathrm{.}00$

Transactions during the year:

a$.$ Purchase, January $302703\mathrm{.}10$

b$.$ Purchase, May $14305\mathrm{.}00$

c$.$ Sale $($$$6$ each$)(130)$

d$.$ Sale $($$$6$ each$)(670)$

Required:

a$.$ Compute the amount of goods available for sale.

b$.$ & c$.$ Compute the amount of ending inventory and cost of goods sold at December $31$ under each inventory costing method.