Buffalo Aircraft doubles the amount of all the inputs it uses—the factory doubles in size and twice as many workers are hired. After this expansion, the number of aircraft produced triples. This means that Buffalo Aircraft is experiencing:
a. increasing marginal cost.
b. economies of scale.
c. increasing average total cost.
d. decreasing the average variable cost.

For each of the following cases determine the ending balance in the inventory account. (hint: first, determine the total cost of inventory available for sale. next, subtract the cost of the inventory sold to arrive at the ending balance.)a. jill’s dress shop had a beginning balance in its inventory account of $40,000. during the accounting period jill’s purchased $75,000 of inventory, returned $5,000 of inventory, and obtained $750 of purchases discounts. jill’s incurred $1,000 of transportation-in cost and $600 of transportation-out cost. salaries of sales personnel amounted to $31,000. administrative expenses amounted to $35,600. cost of goods sold amounted to $82,300.b. ken’s bait shop had a beginning balance in its inventory account of $8,000. during the accounting period ken’s purchased $36,900 of inventory, obtained $1,200 of purchases allowances, and received $360 of purchases discounts. sales discounts amounted to $640. ken’s incurred $900 of transportation-in cost and $260 of transportation-out cost. selling and administrative cost amounted to $12,300. cost of goods sold amounted to $33,900.a& b. cost of goods avaliable for sale? ending inventory?