One of the Methods Permitted by Generally Accepted Accounting Principles

One of the methods permitted by Generally Accepted Accounting Principles for reporting the value of a firm's inventory is weighted-average inventory pricing. The Boswell Corporation began its fiscal year with an inventory of 156 units valued at $10.55 per unit. During the year it made the purchases listed in the following table.
At the end of the year, 239 units remained in inventory. Determine:
a) The weighted-average cost of the units purchased during the year.
b) The weighted-average cost of the beginning inventory and all units purchased during the year.
c) The value of the ending inventory based on the weighted-average cost calculated in b.