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T= o, 2 ( n, 1) x – Casio ClassPad 300 PLUS User Manual

Page 373: Df = 1 c, 1 + (1– c ), 1 c = x

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20050501

2-Sample

t

Test

Command:

TwoSampleTTest

Description: This command compares the population means of two populations when

population standard deviation is unknown. A 2-Sample

t

Test is used for

t

distribution.

t

=

o

1

o

2

x

1 n –1

2

σ

n

1

+

x

2 n –1

2

σ

n

2

o

1

: mean of sample 1 data

o

2

: mean of sample 2 data

x

1

σ

n

-1

: standard deviation of sample 1

x

2

σ

n

-1

: standard deviation of sample 2

n

1

: size of sample 1

n

2

: size of sample 2

This formula is applicable when the population standard deviations of the two
populations are not equal. The denominator is different when the population
standard deviations are equal.

The

t

distribution degrees of freedom

df

and

x

p

σ

n

-1

differ according to whether

the population standard deviations of the two populations are equal.

When the two population standard deviations are equal (pooled)

df

=

n

1

+

n

2

– 2

x

p n

–1

=

σ

n

1

+ n

2

2

(n

1

–1)x

1 n –1

2

+(n

2

–1) x

2 n –1

2

σ

σ

When the two population standard deviations are not equal (not pooled)

df

=

1

C

2

n

1

–1

+

(1–C )

2

n

2

–1

C

=

x

1 n–1

2

σ

n

1

+

x

2 n–1

2

σ

n

2

x

1 n–1

2

σ

n

1

Command Syntax

Syntax 1 (list format)

µ

1

condition”, List(1), List(2), Freq(1) (or 1), Freq(2) (or 1), Pooled condition (On

or Off)
* “Freq” can be omitted. Doing so sets “1” for “Freq”.
* “Pooled” can be omitted. Doing so sets “Off” for “Pooled”.

Syntax 2 (parameter format)

µ

1

condition”,

o

1

value,

x

1

σ

n

-1

value,

n

1

value,

o

2

value,

x

2

σ

n

-1

value,

n

2

value,

Pooled condition (On or Off)
* “Pooled” can be omitted. Doing so sets “Off” for “Pooled”.

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Tests