20021201
Calculation Result Output
Left :
interval lower limit (left edge)
Right :
interval upper limit (right edge)
o
:
mean of sample data
x
σ
n
–1
:
sample standard deviation (Displayed only for list format.)
n
:
sample size
2-Sample
Z
Interval
Command:
TwoSampleZInt
䡺
Description:
This command obtains the confidence interval for the difference between
population means when the population standard deviations of two populations
are known.
The confidence interval is obtained using the following expressions.
The confidence level is 100 (1 –
α
)%.
Left
=
(
o
1
–
o
2
)
–
Z
α
2
Right
=
(
o
1
–
o
2
)
+
Z
α
2
n
1
1
2
σ
+
n
2
2
2
σ
n
1
1
2
σ
+
n
2
2
2
σ
o
1
: mean of sample 1 data
o
2
: mean of sample 2 data
σ
1
: population standard deviation of
sample 1
σ
2
: population standard deviation of
sample 2
n
1
: size of sample 1
n
2
: size of sample 2
Command Syntax
Syntax 1 (list format)
C-Level value,
σ
1
value,
σ
2
value, List(1), List(2), Freq(1) (or 1), Freq(2) (or 1)
* “Freq” can be omitted. Doing so sets “1” for “Freq”.
Syntax 2 (parameter format)
C-Level value,
σ
1
value,
σ
2
value,
o
1
value,
n
1
value,
o
2
value,
n
2
value
Definition of Terms
C-Level : confidence level (0
<
C-Level < 1)
σ
1
:
population standard deviation of sample 1 (
σ
1
> 0)
σ
2
:
population standard deviation of sample 2 (
σ
2
> 0)
List(1) :
list where sample 1 data is located
List(2) :
list where sample 2 data is located
Freq(1) : frequency of sample 1 (1 or list name)
Freq(2) : frequency of sample 2 (1 or list name)
o
1
:
mean of sample 1 data
n
1
:
size of sample 1 (positive integer)
o
2
:
mean of sample 2 data
n
2
:
size of sample 2 (positive integer)
7-10-3
Confidence Intervals
