60. Although airline schedules and cost are important factors for business travelers when choosing an airline carrier, a USA Today survey found that business travelers list an airline’s frequent flyer program as the most important factor. From a sample of n  1993 business travelers who responded to the survey, 618 listed a frequent flyer program as the most important factor.

a. What is the point estimate of the proportion of the population of business travelers who believe a frequent flyer program is the most important factor when choosing an airline carrier?

b. Develop a 95% confidence interval estimate of the population proportion.

c. How large a sample would be required to report the margin of error of .01 at 95% confidence? Would you recommend that USA Today attempt to provide this degree of precision? Why or why not?