. The following table provides actual data on the retail price and sales of instant and roasted coffee in the United States over 1997 and 1998. Retail price of Sales of Retail price of Sales of Instant Coffee Instant Coffee Roasted Coffee Roasted Coffee (33 / lb (Million lbs. ) $ / lb ) (Million lbs) 1997 10 35) 4.11 1998 10. 48 3. 76 Use the midpoint formula to calculate the cross price elasticity of demand between roasted and instant coffee. For this, calculate the change in quantity demanded of roasted coffee between 1997 and 1998 in response to the change in the price of instant coffee over the same period