Final answer:
The surplus or shortage when the price is $18 can be determined by substituting the price into the demand and supply functions and solving for the quantity. In this case, there is a surplus of 62.10.
Step-by-step explanation:
Given the demand and supply functions:
P = 60Q + 59
P = -4Q + 227
We need to determine the surplus or shortage at a price of $18. To do this, we substitute P = 18 into both equations and solve for Q:
For demand: 18 = 60Q + 59
For supply: 18 = -4Q + 227
After solving, we find that the quantity demanded is 0.15 and the quantity supplied is 62.25. Therefore, there is a surplus of 62.25 - 0.15 = 62.10.