56. Cincinnati/Northern Kentucky International Airport had the second highest on-time arrival rate for 2005 among the nation’s busiest airports (The Cincinnati Enquirer, February 3, 2006). Assume the findings were based on 455 on-time arrivals out of a sample of 550 flights.

a. Develop a point estimate of the on-time arrival rate (proportion of flights arriving on time) for the airport.

b. Construct a 95% confidence interval for the on-time arrival rate of the population of all flights at the airport during 2005.