Question

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 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 business travelers follow. 6 10 2 6 3 3 3 6 6 6 6 5 8 9 10 10 7 9 3 6 5 10 9 9 10 3 8 6 6 3 3 6 6 5 4 10 9 3 5 7 10 6 3 8 6 8 3 3 5 5 Develop a confidence interval estimate of the population mean rating for Miami. Round your answers to two decimal places.

Answer 1

(5.4582 ; 6.8618)

Explanation:

Given the data:

6 10 2 6 3 3 3 6 6 6 6 5 8 9 10 10 7 9 3 6 5 10 9 9 10 3 8 6 6 3 3 6 6 5 4 10 9 3 5 7 10 6 3 8 6 8 3 3 5 5

Sample mean, xbar = Σx / n

n = sample size = 50

ΣX = 308

xbar = 308 / 50 = 6.16

Using a Calculator :

The sample standard deviation, s = 2.469

Confidence interval = xbar ± margin of error

Margin of Error = Tcritical * s/sqrt(n)

Tcritical at 95% ; df = 50 - 1 = 49

Tcritical = 2.010

Hence,

Margin of Error= 2.010 * (2.469/sqrt(50)) = 0.7018

Lower boundary : (6.16 - 0.7018) = 5.4582

Upper boundary : (6.16 + 0.7018) = 6.8618

(5.4582 ; 6.8618)