User Guide

20050501
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