As the price of margarine rises by 20%, a manufacturer of baked goods increases its quantity of butter demanded by 5%. Calculate the cross-price elasticity of demand between butter and margarine. Are butter and margarine substitutes or complements for this manufacturer? b. After Malia’s income increased from $12,000 to $18,000 a year, her purchases of album downloads increased from 10 to 40 downloads a year. Calculate Malia’s income elasticity of demand for albums. c. Expensive restaurant meals are income-elastic goods for most people, including Sanjay. Suppose his income falls by 10% this year. What can you predict about the change in Sanjay’s consumption of expensive restaurant meals?