When a certain brand of dog food sells for $20 per bag, 10,000 units are sold; when the price changes to $22, 8000 units are sold. Calculate its price elasticity of demand. Enter only numbers, a decimal point, and/or a negative sign as needed, Round your answer to two decimal places as necessary, when rounding on Intermediate steps, use four places. Consider again the dog food from the last question. Demand for this dog food is O unit elastic O (relatively) elastic O inferior O (relatively) inelastic O normal