A sample survey is designed to estimate the proportion of sports utility vehicles being driven in the state of California. A random sample of 500 registrations are selected from a Department of Motor Vehicles database, and79are classified as sports utility vehicles.

(a) Use a 95% confidence interval to estimate the proportion of sports utility vehicles in California. (Round your answers to three decimal places.)

__to__

(b) How can you estimate the proportion of sports utility vehicles in California with a higher degree of accuracy? (HINT: There are two answers. Select all that apply.)

decreasez_/2by decreasing the confidence coefficient

decrease the sample sizen

decreasez_/2by increasing the confidence coefficient

increasez_/2by decreasing the confidence coefficient

increasez_/2by increasing the confidence coefficient

conduct a non-random sample

increase the sample sizen