Final answer:
The price elasticity of demand is calculated by dividing the percentage change in quantity demanded by the percentage change in price.
Step-by-step explanation:
The subject of this question is Mathematics. The question asks about the price elasticity of demand, which is a concept in Economics to measure how the quantity demanded changes in response to a change in price.
The formula to calculate price elasticity of demand is: Price elasticity of demand = Percentage change in quantity demanded / Percentage change in price. In this case, the percentage change in price is 4% (as calculated), and the percentage change in quantity demanded is -1% (since it decreases by 1% an hour).
Applying the formula, we would have: Price elasticity of demand = (-1% / 4%) = -0.25. Therefore, the price elasticity of demand is -0.25.