Below are the TOTAL COSTS at different levels of output for Merkley Corporation: Production Cost X Cost Y Cost z 20,500 units $18,325 $18,450 $10,750 26,000 units $21,900 $23,400 $10,750 What type of cost are cost X, Y, and Z? X is a mixed cost, Y is a variable cost, Z is a fixed cost X is a variable cost, Y is a mixed cost, Z is a fixed cost X is a mixed cost, Y is a fixed cost, Z is a mixed cost X is a fixed cost, Y is a mixed cost, Z is a variable cost