The Following Units Are Available for Sale During the Year

The following units are available for sale during the year: $\begin{array}{lll}\text { January 1 } & \text { Beginning Inventory } & 10 \text { units at } \$ 18 \text { each } \\\text { April } 3 & \text { Purchase } & 30 \text { units at } \$ 20 \text { each } \\\text { August } 31 & \text { Purchase } & 28 \text { units at } \$ 25 \text { each } \\\text { September } 29 & \text { Purchase } & 17 \text { units at } \$ 30 \text { each } \\\text { December } 31 & \text { Ending Inventory } & 21 \text { units }\end{array}$ Determine ending inventory cost by (a) FIFO method, (b) LIFO method, and (c) average cost method.