Suppose the price of gasoline in July 2017 averaged $2.35 a gallon and 15 million gallons a day were sold. In October 2017the price averaged $3.05 a gallon and 14 million gallons were sold. If the demand for gasoline did not shift between these two months, use the midpoint formula to calculate the price elasticity of demand. Indicate whether demand was elastic or inelastic .