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Chapter 14: Hypothesis Tests – Small Samples
Section Review
14-3 Small Sample HypothesisTests for the DifferenceBetween
Two PopulationMeans Using Independent Samples
There may be situations in which one must decide whether the observed
difference between two sample means is due to chance or whether the
difference is due to the fact that the corresponding population means are not
the same or that the means are from different populations. In this section we
will discuss tests for such problems when the samples are small and the
population standard deviations are unknown.
Figure 14-11
shows the experimental display of the sampling populations
with respective means and standard deviations. Recall, for this case the
sampling populations are assumed to be normally distributed. Independent
random samples will be selected from each population with unknown means
and variances. The sample sizes will be less than 30.
Figure 14-11:
Experimental Display for Sampling from
Two Independent Populations
The point estimate for the difference between the two population means
and
is the difference between the respective sample means
̅
and
̅
.
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