July 2012
Intermediate to advanced
400 pages
9h 33m
English
Let us develop the following notation. The population regression line will be written as
(12.4) ![]()
and the sample regression line will appear as
where
is the sample estimate of
and
is the sample estimate of
. The sample regression line is illustrated in Fig. 12.4. Note that there are two values of Y that occur at each Xi value—the observed value of Y or Yi, and the estimated value of Y or
. Their difference,
, will be termed the ith residual or ith deviation from the sample regression line. This residual is “observed” and serves as an estimate of εi, which is purely random and thus “unobserved.”
Figure 12.4 The ...
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