Readers Question: How would I the price elasticity of demand if the mean price is $7.50 and the mean quantity is 20,000? I don’t even know where to begin. My text book does not offer a proper equation for a problem with missing numbers.
Yes, to calculate elasticity of demand you would need to know the change in price and change in quantity.
There are different ways of calculating the % change in price and demand. It can be either arc elasticity of demand (taking mid point) or point elasticity
Prices Elasticity of demand calculates how responsive demand is to a change in price. With the two figures above, you cannot calculate elasticity. You would need to know two points on the demand curve.