ClassPad 330 Plus Manual

20090601
7-10-6
Confidence Intervals
u
Program, eActivity or Main Application
Command: OnePropZInt

Command Syntax
C-Level value,
x
value,
n
value
Input Example:
OnePropZInt 0.99,2048,4040
2-Prop
Z
Interval
Menu: [Interval]-[Two-Prop ZInt]
Description: This command obtains the confidence interval of the difference between the
proportions of successes of two populations.
The confidence interval is obtained using the following expressions.
The confidence level is 100 (1 –
α
)%.
Lower = – – Z
α
2
x
1
n
1
x
2
n
2
n
1
n
1
x
1
1–
n
1
x
1
+
n
2
n
2
x
2
1–
n
2
x
2
Upper = – + Z
α
2
x
1
n
1
x
2
n
2
n
1
n
1
x
1
1–
n
1
x
1
+
n
2
n
2
x
2
1–
n
2
x
2
n
1
,
n
2
: sample size
x
1
,
x
2
: data
Definition of Terms
C-Level: confidence level (0
<
C-Level < 1)
x
1
: data value (integer,
x
1
>
0) of sample 1
n
1
: size of sample 1 (positive integer)
x
2
: data value (integer,
x
2
>
0) of sample 2
n
2
: size of sample 2 (positive integer)
Calculation Result Output
Lower : interval lower limit (left edge)
Upper : interval upper limit (right edge)
ˆp
1
: estimated proportion of sample 1
ˆp
2
: estimated proportion of sample 2
n
1
: size of sample 1
n
2
: size of sample 2