Two–Sample Z–Interval
Menu name
Inputs
Results
Inference aplet
Z–INT:
–
This option uses the Normal Z–distribution to calculate a
confidence interval for the difference between the means of
two populations,
–
, when the population standard
deviations,
and
, are known.
1
2
The inputs are:
Field name
Definition
Sample 1 mean.
x1
Sample 2 mean.
x2
n1
Sample 1 size.
n2
Sample 2 size.
1
Population 1 standard deviation.
2
Population 2 standard deviation.
C
Confidence level.
The results are:
Result
Description
Critical Z
Critical value for Z.
Lower bound for
Min
Upper bound for
Max
–
.
1
2
–
.
1
2
9-17