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Chapter 11: Confidence Intervals – Large Samples
487
Used this information to construct a 98% confidence interval for the average
weight of all the backpacks filled with books, computers etc. which are
carried around on that campus by the students. Assume that the population
of these weights is normally distributed.
Solution:
The
Large Sample Confidence Interval for a Single
Population Mean
workbook is designed to use both summary information as
well as data. Thus, we will use this workbook to help solve for 98%
confidence interval. Now we are not given the standard deviation for the
population. All we know about the population is that it is normally
distributed. Thus we will have to use that portion of the workbook which
uses these properties. The output from the workbook is given in
Figure 11-12
. This portion of the workbook will compute the sample mean
(15.23) as well as the sample standard deviation (4.022) as shown in
Figure
11-12
.