Answer: Elasticity is -1.2
Step-by-step explanation:
Price elasticity of demand measures the responsiveness of quantity demand to a change in the price of the good.
Change in price = $7 - $5 = $2
Change in Quantity = 100 - 150 = - 50
Elasticity using the Ac method is,



Thus, elasticity of demand for appetizers is -1.2.