Price elasticity of supply is calculated as:

The price elasticity of supply measures how responsive the quantity supplied of a good or service is to a change in its price. This concept is critical in understanding how producers adjust their supply levels when prices fluctuate.

The correct calculation involves the percentage change in the quantity supplied divided by the percentage change in price. This formula captures the relationship between supply and price changes effectively, indicating how much supply will increase or decrease in response to a price change. A higher elasticity value signifies that supply is very responsive to price changes, while a lower value indicates that supply is less sensitive.

Other options do not accurately represent this relationship. The second option reverses the relationship and instead presents price elasticity of demand. The third and fourth options provide a ratio of price to quantity supplied or quantity supplied to price, which do not incorporate the percentage changes necessary to assess elasticity properly. Understanding the proper formulation helps economists and businesses understand market dynamics and make informed decisions.