Public Policy and Political Science
California law requires fuel outlets to install special catch basins designed to contain gasoline leaks in underground storage tanks. Owners who do not comply can face stiff fines and other penalties. Independent random samples of gasoline stations around Los Angeles and around San Francisco were obtained, and each station was inspected for catch basins. Sixteen of 140 stations near Los Angeles had no catch basins, and 12 of 126 in San Francisco were not complying with the law.
a. Find the sample proportion of stations without catch basins near each city. Verify the nonskewness criterion.
b. Is there any evidence that the population proportion of stations in noncompliance with the law is different near Los Angeles and near San Francisco? Use a = 0.01.