# demand & Supply

posted by
**Albert jason** on
.

If the demand for butter rises by 4% while the price of margarine rises by 8%, then calculate the cross price elasticity of demand of butter with respect to the price of margarine?

The formula for the cross-price elasticity is (%change in Qa)/(%change in Pb) Where Qa is the quantity demanded of good a, and Pb is the price of good b. Apply this formula. You have all the information you need.