Answer: 20%
Step-by-step explanation:
The price elasticity of demand shows the increase in quantity demanded as a result of a decrease in price and vice versa.
It is calculated by the formula:
Price elasticity of demand = Change in quantity demanded / Change in price
The formula can therefore be used to find the increase in quantity. Price elasticities are usually denoted in negatives even if not shown so:
-4 = x / -5%
x = -4 * -5%
x = 20%