The demand function for good X is ln QXd = a + b ln PX + c ln M + e, where Px is the price of good X and M is income. Least squares regression reveals that: a. If M = 55,000 and Px = 4.39, compute the own price elasticity of demand based on these estimates. Determine whether demand is elastic or inelastic. b. If M = 55,000 and Px = 4.39, compute the income elasticity of demand based on these estimates. Determine whether X is a normal or inferior good. Income elasticity of demand:X is .