Arrange the following changes in the correct order of occurrence when demand for a product increases in a perfectly competitive industry currently in long run equilibrium. Existing firms earn positive profits. Demand curve shifts to the right. Supply curve shifts to the right. New firms decide to enter the market.

1.Existing firms earn positive profits.

2.Demand curve shifts to the right.

3.Supply curve shifts to the right.

4.New firms decide to enter the market.