products x, y, and z are produced from the same process at a cost of $5,340. five thousand pounds of raw material yields 2,300 x, 3,300 y, and 1,800 z. selling prices are: x $2 per unit, y $4 per unit, and z valueless. the ending inventory of x is 66 units. what is the value of the ending inventory if joint costs are allocated using net realizable value?