how to solve

Winston uses the high-ow method. It had an average cost per unit of $700 at its lowest level of activity when sales equaled 10,000 units and an average cost per unit of $4.55 at its highest level of activity when sales equaled 20,000 units What would Winston estimate its total cost to be if sales equaled 7000 units? Multiple Choice $32,000 $14,700 $49,000