Suppose that c left parenthesis x right parenthesis equals 5 x cubed minus 70 x squared plus 12 comma 000 x is the cost of manufacturing x items. Find a production level that will minimize the average cost of making x items. Question content area bottom Part 1 The production level that minimizes the average cost of making x items is xequals 7 . (Simplify your answer.) Part 2 At this level, the average cost of making x items is $11935 . (Simplify your answer.)