Exercise 21-3 Cost behavior identification LO C1 Following are five sertes of costs A through E measured at varlous volume levels. Examine each series and Identify which is fixed, varlable, mixed, step-wise, or curvilinear Volume Series A Series B Series C (Units) Series D Series E $ 3,600 7,200 10,800 14,400 18,000 $2,500 3,100 3,700 4,300 4,900 5,500 6,100 $ $5,000 $1,000 1,000 2,000 2,000 3,000 3,000 4,000 400 5,000 s,000 5,000 5,000 5,000 5,000 6,000 6,600 7,200 8,200 9,600 13,500 800 1,200 1,600 2,000 2,400 21,600 Series A Series B Series C Series D Curvilinear cost Series E Fixed cost Mixed cost Step-wise cost