The accompanying data represent one-way commuting times (minutes) for a simple random sample of 15 persons who work at a large assembly plant. The data are also in file XR09082. Assuming an approximately normal distribution of commuting times for those who work at the plant, construct and interpret the 90% and 95% confidence intervals for the mean.
21.7
|
26.8
|
33.1
|
27.9
|
23.5
|
39.0
|
28.0
|
24.7
|
28.4
|
28.9
|
30.0
|
33.6
|
33.3
|
34.1
|
35.1
|