e average cost of a turntable is given by C(x) = 140,000x+30+0.02x dollars per turntable. Week oduction is currently 3,000 and is increasing at a rate of 120 turntables per week. What is the average cost of producing 3000 boats? B. How is the average cost changing per week? Is it increasing or decreasing? dC dx (Hint: Find when x = 3,000 and = 120) dt