Question

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports....

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a rating for the Miami International Airport. The ratings obtained from the sample of 50 business travelers follow.

1 5 6 7 8 8 8 9 9 9 9 10 3

4 5 5 7 6 8 9 10 5 4 6 5 7

3 1 9 8 8 9 9 10 7 6 4 8 10

2 5 1 8 6 9 6 8 8 10 10

Develop a confidence interval estimate of the population mean rating for Miami. Round your answers to two decimal places.

for above data:

from excel function average(array): mean =6.76

from function stdev(array) =2.552

 sample mean 'x̄= 6.76 sample size   n= 50 sample std deviation s= 2.552 std error 'sx=s/√n=2.552/√50 = 0.3609
 for 95% CI; and 49 df, value of t= 2.010 margin of error E=t*std error    = 0.725 lower bound=sample mean-E = 6.035 Upper bound=sample mean+E = 7.485 from above 95% confidence interval for population mean =(6.03,7.49)