How external costs are example of market failure

Alocal club is selling christmas trees and deciding how many to stock for the month of december. if demand is normally distributed with a mean of 100 and standard deviation of 20, trees have no salvage value at the end of the month, trees cost $20, and trees sell for $50 what is the service level?

Hours to produce one unit worker hours to produce yarn country a 8 hours country b 4 hours worker hours to produce fabric counrty a 12 hours country b 13 hours additional worker hours to produce fabric instead of yarn country a ? country b? which of the follow is true of the trade relationship between country a and country b? country a has an absolute advantage in producing yarn and fabric country b has an absolute advantage in producing yarn and fabric country b has a comparative advantage to country a in producing fabric country a has a comparative advantage to country b in producing fabric

In june 2009, at the trough of the great recession, the bureau of labor statistics announced that of all adult americans, 140,196,000 were employed, 14,729,000 were unemployed and 80,729,000 were not in the labor force. use this information to calculate: a. the adult population b. the labor force c. the labor-force participation rate d. the unemployment rate