Interpreting
a confidence interval for a mean
A confidence interval can be expressed
as:
p ± m
m is called the margin of error
m is called the margin of error
pTwo endpoints of an interval:
m possibly within ( − m) to ( + m)
Example: 114 to 126
m possibly within ( − m) to ( + m)
Example: 114 to 126
A confidence level C (in %) indicates
the success rate of the method
that produces the interval.
It represents the
area under the normal curve
within ± m of the center
of the curve.
m
m
