Question

Plus sign attached to measure their price elasticity of supply

Answer 1

Heya...

Price elasticity refers to degree of % change in Quantity supplied with respect to % change in own price of the commodity...

It's formula is....
% change in qu supplied / % change in price of commodity....

* In this plus sign is prefixed because here is positive relationship between own price of commodity and quantity supplied.....

* So producer want to sell more on more price ....