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Chapter 13: Confidence Intervals – Small Samples
Figure 13-5
: Display of the experimental situation
in selecting the sample to estimate the
population mean
The point estimate for the population mean
is the sample mean
̅
and the
point estimate for the population standard deviation
is the sample standard
deviation
.
The general equation used in constructing a (1 -
)
100 percent confidence
interval for the population mean
when the population standard deviation
is unknown and the sample size is small (
< 30) is given by