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Chapter 13: Confidence Intervals – Small Samples
Figure 13-6:
Workbook Output with the Confidence
Interval for
Example 13-3
Example 13-4:
The president of a large community college wishes to
estimate the average distance commuting students’ travel to the campus. A
sample of 12 students was randomly selected and yielded the following
distances: 37, 25, 23, 20, 29, 35, 28, 32, 37, 27, 23, and 40.
Construct a 95% confidence interval estimate for the true mean distance
commuting students travel to the campus.
Solution:
Since raw data are given, we need to find the sample mean and
the sample standard deviation. These values are
̅
= 29.6667 and
s
= 6.4854
(Verify). Also, we are given
= 0.05,
/2 = 0.025,
= 12,
= 12-1 = 11,
so
= = 2.201, and
̅
√
= 1.8722.
Click here for the Small Sample Confidence Interval for a Single Population Mean Workbook