How to use a supply-and-demand graph and assuming competitive markets, show and explain the effect on equilibrium price and quantity of the following: 

1. A technological change that reduces the cost of producing X-rays on the market for physician clinic services.
2. Increased graduations of new doctors on the market for physician services.
3. The virtual elimination of smoking in the population on the market for hospital services.
4. A price ceiling placed on physician fees in the market for physician services.