ClassPad 330 Plus Manual
20090601
Input Example:
Syntax 1 (list format)
TwoSampleZInt 0.95,15.5,13.5,list1,list2,1,1
Syntax 2 (parameter format)
TwoSampleZInt 0.95,1,1.5,418,40,402,50
1-Prop 
Z
 Interval 
Menu: [Interval]-[One-Prop ZInt]
Description: This command obtains the confidence interval of the proportion of successes 
in a population. 
  The confidence interval is obtained using the following expressions. 
The confidence level is 100 (1 –
 α
)%. 
n
: sample size 
x
: data
Definition of Terms 
C-Level: confidence level  (0 
<
 C-Level < 1)
x
 :  data (0 or positive integer) 
n
 :  sample size (positive integer) 
Calculation Result Output
Lower :  interval lower limit (left edge) 
Upper :  interval upper limit (right edge) 
ˆ p
:    estimated sample proportion 
n
 :    sample size
Example
Data : 2048
Sample size : 4040
Significance level : 1% ( = confidence level : 99%)
• Statistics Wizard Operation
(1) On the menu bar, tap [Calc] and then [Interval].
(2) Select [One-Prop ZInt] and then tap [Next >>]. 
(3) Input values. 
(4) Tap [Next >>]. 
α
2
Lower =  – Z
x
n
n
1
n
x
n
x
1–
Upper =  + Z
x
n
α
2
n
1
n
x
n
x
1–
α
2
Lower =  – Z
x
n
n
1
n
x
n
x
1–
Upper =  + Z
x
n
α
2
n
1
n
x
n
x
1–
7-10-5
Confidence Intervals










