Use the following table to answer the following questions. Price of Quantity demanded when Quantity demanded when T-shirts the average income is $20 the average income is $30 000 000 4 3000 5000 2400 4200 1600 3000 800 1800 a) Calculate the price elasticity of demand when the price of a T-shirt rises from $5 to $6 and the income is $20 000. Also calculate it when the income is $30 000. b) Calculate the income elasticity of demand when the price of the average income rises from $20 000 to $30 000 and the price of a T-shirt is $4. Also calculate it when the price is $7