20021201
Confidence Interval Command List
k
Z
Confidence Interval
1-Sample
Z
Interval
Command:
OneSampleZInt
䡺
Description:
This command obtains the confidence interval for the population mean when
the population standard deviation is known.
The confidence interval is obtained using the following expressions.
Left
=
o
–
Z
α
2
σ
n
Right
=
o
+
Z
α
2
σ
n
α
is the significance level, and 100 (1 –
α
)% is the confidence level. When the
confidence level is 95%, for example, you would input 0.95, which produces
α
= 1 – 0.95 = 0.05.
Command Syntax
Syntax 1 (list format)
C-Level value,
σ
value, List, Freq (or 1)
* “Freq” can be omitted. Doing so sets “1” for “Freq”.
Syntax 2 (parameter format)
C-Level value,
σ
value,
o
value,
n
value
Definition of Terms
C-Level : confidence level (0
<
C-Level < 1)
σ
:
population standard deviation (
σ
> 0)
List :
list where sample data is located
Freq :
frequency of sample (1 or list name)
o
:
mean of sample data
n
:
sample size (positive integer)
Input Example:
Syntax 1 (list format)
OneSampleZInt 0.95,1,list1,1
Syntax 2 (parameter format)
OneSampleZInt 0.95,1,64.3,20
7-10-2
Confidence Intervals
