Enterprise Rent-A-Car executives believe that Enterprise accounts for about 50% of all Mustangs which are rented. To test this belief a researcher randomly surveys major airports with on-site rental car lots. Observers are sent to each location and instructed to record the number of rental company Mustangs observed in a four-hour period. About 500 are observed, and 30% are observed being returned to Enterprise. Is there statistical evidence to support the claim of the executives? Conduct a complete (5 step) hypothesis test using a .05 significance level (95% confidence).