Casio FXCP400 Lower, Upper = (o1 – o2)  Z, Lower, Upper, Lower, Upper, Lower, Upper = ￿o￿o￿￿ ￿ ￿￿￿￿, Interval, 1-Sample, Interval, 2-Sample, Interval, Interval

2-ProportionZ Interval .... [Interval] - [Two-Prop Z Int]

Calculates the confidence interval for the difference between population proportions based on the difference between two sample proportions.

To specify the data below and perform a 1-SampleZ Interval calculation list1: {299.4, 297.7, 301, 298.9, 300.2, 297}

Population standard deviation: 3

Significance level: 5% ( = confidence level: 95%)

1-SampleZ Interval .... [Interval] - [One-Sample Z Int]	Lower, Upper = o  Z	α	σ
		2
				n

Calculates the confidence interval for the population mean based on a sample mean and known population standard deviation.

0708

2-SampleZ Interval .... [Interval] - [Two-Sample Z Int]

Lower, Upper = (o1 – o2)  Z

α

σ

2

σ 2

1

+

2

2

n1

n2

Calculates the confidence interval for the difference between population means based on the difference

between sample means when the population standard deviations are known.

Lower, Upper =

x

 Z

1-ProportionZ Interval .... [Interval] - [One-Prop Z Int]

α

1 x

1–

x

n

2

n n

n

Calculates the confidence interval for the population proportion based on a single sample proportion.

Lower, Upper

x1 – x2  Z n1 n2

=
	x1	1–	x1		x2	1–	x2
	n1		n1				n2
α				+	n2
2		n1				n2

1-Samplet Interval .... [Interval] - [One-Sample t Int]	Lower, Upper = o  tn –1	α	sx
		2
				n

Calculates the confidence interval for the population mean based on a sample mean and a sample standard deviation when the population standard deviation is not known.

2-Samplet Interval .... [Interval] - [Two-Sample t Int]

Calculates the confidence interval for the difference between population means based on the difference between sample means and sample standard deviations when the population standard deviations are not known.

￿ When the two population standard deviations



Lower, Upper = ￿o￿o￿￿ ￿ ￿￿￿￿

s￿







are equal (pooled)

￿

￿

￿

s=

(( 1 – 1)s12 + (

2 – 1)s22)/(

1 +

2 – 2)

￿ When the two population standard deviations

α

s

2

s

2

are not equal (not pooled)

Lower, Upper = (o1 – o2) tdf

x1

+

x2

2

n1

n2

df = 1/(C2/(n

1

– 1) + (1 – C)2/(n

2

– 1))

C = (s

2/n

)/(s

2/n

1

+ s

2/n

)

x1 1

x1

x2

2

General Confidence Interval Precautions

If you input a C-Level (confidence level) value in the range of 0 s C-Level < 1, the value you input is used. To specify a C-Level of 95%, for example, input “0.95”.

Chapter 7: Statistics Application 144