The units of an item available for sale during the year were as follows:

Jan. 1 Inventory 2,500 units at $5

Feb. 17 Purchase 3,300 units at $6

July 21 Purchase 3,000 units at $7

Nov. 23 Purchase 1,200 units at $8

There are 1,500 units of the item in the physical inventory at December 31. The periodic inventory system is used.

a. Determine the inventory cost by the first-in, first-out method. $ 11700

b. Determine the inventory cost by the last-in, first-out method. $ 7500

c. Determine the inventory cost by the weighted average cost method. $ _____