Suppose the average income of a consumer named Warren decreases from R15000 to R12000. As a result, the quantity of product A demanded by Warren increases from 260 units to 280 units. 4.1.1. Use the ARC (midpoint) formula to calculate the income elasticity of demand for product A given the information above. (3) 4.1.2. Based on your answer in 4.1.1, is product A an inferior good or a normal good? Substantiate your answer with reference to your calculated elasticity value.