1. Suppose the short-run demand for a product is give by QD = 200 - 2P + 41 where I is the average income of consumers measured in thousands of dollars. Suppose the short-run supply curve is Qs = 3P - 50 (a) If I = 25, find the market-clearing price and quantity for the product. (b) If I = 50, find the market-clearing price and quantity for the product. (c) Explain what is meant by a demand shifter and why income is a demand shifter but price is not