Consider the market for Rainbow sandals. Suppose average household income increases from $44 thousand to $61 thousand per year. As a result, the demand for Rainbow sandals increases from 329 to 525. Using the midpoint formula, what is the income elasticity of demand for Rainbow sandals? nothing. (Enter a numeric response using a real number rounded to two decimal places.) In this instance, Rainbow sandals are a normal good. Furthermore, Rainbow sandals are a luxury .