10 . Individual Problems 6-3 An end-of-aisle price promotion changes the price elasticity of a good from -3 to -4. Suppose the normal price is $18, which equates marginal revenue with marginal cost at the initial elasticity of -3. What should the promotional price be when the elasticity changes to -4? (Hint: In other words, what price will equate marginal revenue and marginal cost?) O $12.80 O $16.00 O $9.60 O $20.80 Grade It Now Save & Continue Continu without saving