suppose there are 11 buyers and 11 sellers, each willing to buy or sell one unit of a good, with values {$14, $13, $12, $11, $10, $9, $8, $7, $6, $5, $4,}. assume no transaction costs and a competitive market, what is the equilibrium price in this market? a. 7 b. 8 c. 9 d. 10