I need help understanding this exercise:

11. Suppose the demand and wheat are shown in the accompanying table. # of bushels demanded Price per bushel # of bushels supplied Surplus(+) or Shortage(-) 85 $3.40 65 80 3.70 70 75 4.00 75 70 4.30 80 65 4.60 85 a. What is the equilibrium price? What is the equilibrium quantity? Fill in the surplus shortage column and use it to explain why your answers are correct. b. Graph the demand for wheat and the supply of wheat. Label the equilibrium price and quantity. c. Why will $3.40 not be the equilibrium price? Why not $4.60