Below is a set of projects aimed at cleaning up a city's recreational areas.
Determine whether the city should undertake the cleanup effort. Assume the city has enough money in its budget to undertake all projects.

Project Marginal Cost Marginal Benefit Clean Up? (Y/N)
North Park $13,000 $16,000
Upper River Beach 6,000 8,000
South Shore 29,000 30,000
Green Creek 900 1,300