Casio FX-9860G Left, 1(Z), Right, xσn-1, 2(2-S), 4(INTR), of sample, of sample, mean of sample, size of sample, : mean of sample, : mean of sample, n1 : size of sample

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Confidence Interval

After setting all the parameters, use c to move the highlighting to “Execute” and then press the function key shown below to perform the calculation.

• 1(CALC) ... Performs the calculation.

Calculation Result Output Example

Left ..............................	confidence interval lower limit (left edge)
Right ............................	confidence interval upper limit (right edge)
x¯ ..................................	mean of sample
xσn-1 .............................	sample standard deviation
	(Displayed only for Data: List setting.)
n ..................................	size of sample

u 2-Sample Z Interval

2-SampleZ Interval calculates the confidence interval for the difference between two population means when the population standard deviations of two samples are known.

The following is the confidence interval. α is the level of significance. The value 100 (1 – α) % is the confidence level.

Left = (o1 – o2) – Z

α

σ 2

+

σ 2

x¯1

: mean of sample 1

1

2

x¯2

: mean of sample 2

2

n1

n2

α

σ1

: population standard deviation

Right = (o1 – o2) + Z

σ 2

+

σ 2

of sample 1

1

2

2

n1

n2

σ2

: population standard deviation

of sample 2

n1 : size of sample 1

n2 : size of sample 2

Perform the following key operations from the statistical data list.

4(INTR)

1(Z)

2(2-S)

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