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Left = – – z α 2 x, 1– n, Right = – + z α 2 x – Casio ClassPad 300 PLUS User Manual

Page 384

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20050501

2-Prop

Z

Interval

Command:

TwoPropZInt

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)%.

Left = – – 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

Right = – + 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

Command Syntax

C-Level value,

x

1

value,

n

1

value,

x

2

value,

n

2

value

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)

Input Example:

TwoPropZInt 0.95,132,200,90,150

Calculation Result Output

Left :

interval lower limit (left edge)

Right :

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

7-10-5

Confidence Intervals