Information Technology Reference
In-Depth Information
.4
0
-3
3
Normally distributed variable
FIGURE 7.1
Bell-Shaped Symmetric Curve of a Normal Distribution.
6
0
135
170
Height (cm)
FIGURE 7.2
Histogram of Heights in a Sixth-Grade Class.
If your objective is to report the precision of your estimate of the mean
or median, then the standard error may be meaningful providing the mean
of your observations is normally distributed.
The good news is that the sample mean often will have a normal distri-
bution even when the observations themselves do not come from a
