An individual's income rises from $80,000 per year to $84,000 per year, and as a consequence, the

Question:

An individual's income rises from $80,000 per year to $84,000 per year, and as a consequence, the person's purchases of movie downloads rise from 48 per year to 72 per year. What is this individual's income elasticity of demand? Are movie downloads a normal or inferior good?