Question: Sample Mean Distribution Example: O'Hare Airport Service Rate.
The O'Hare International Airport surverys business travelers to evaluate their service rate. Suppose a simple random sample of 12 business travelers have been asked to rate the airport service, the survey shows:
Person 1: 8
Person 2: 10
Person 3: 8
Person 4: 6
Person 5: 9
Person 6: 6
Person 7: 7
Person 8: 7
Person 9: 8
Person 10: 9
Person 11: 8
Person 12: 7
Where Sample Mean = 7.75 ; Sample S.D. = 1.215

a. What are the population distribution, sample distribution, and sample mean distribution of the service rate of O'Hare International Airport?

b. What is the confidence interval of the average service rate at 95% and 90%?