I am seeking an explanation for question 3 and 4, How do I illustrate a supply - demand curve with no given numbers. How do I show a short term effect on equilibrium price . Also how do I illustrate substitute goods differently. Also an explanation for question 4

3. An increase in labor-costs has made operating public bus systems very expensive. Management decides to pass the costs on to bus riders. a. Illustrate on a supply-demand curve the short-term effect on the equilibrium price and quantity of bus rides? a. Suppose bus rides and used autos are substitute goods. [1lustrate on a supply and demand curve the change in equilibrium prices and quantities for used cars. L] 4. A very small midwestern city raises the price of parking in its municipal deck from $3 to $5 per day. They saw that the number of cars using the deck fell from 1,200 to 900 per day. Use the mid-point method to calculate the price elasticity of demand. Compare the revenue earned by the municipality with the new price and demand compared to the old price and demand. Consider this answer in light of the price elasticity of demand you just calculated. Is this answer for revenue consistent with what you observed for the price elasticity of demand