Casio FX-9860G x1, u 2-Prop Z Interval, Left = x1 – x2 – Z α, Right = x1 – x2 +Z α

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Confidence Interval

u 2-Prop Z Interval

2-PropZ Interval uses the number of data items to calculate the confidence interval for the defference between the proportion of successes in two populations.

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

Left = x1 – x2 – Z α

n1 n22

Right = x1 – x2 +Z α

n1 n22

								n1, n2 : size of sample
x1		x1			x2		x2
								x1, x2	: data
n1 1– n1					n2 1– n2
			+
	n1					n2
	x1	x1				x2	x2
	n1	1– n1		+		n2	1– n2
		n1					n2

Perform the following key operations from the statistical data list.

4(INTR)

1(Z)

4(2-P)

Data is specified using parameter specification. The following shows the meaning of each item.

C-Level .........................	confidence level (0 < C-Level < 1)
x1 .................................	data value (x1 > 0) of sample 1
n1 .................................	size (positive integer) of sample 1
x2 .................................	data value (x2 > 0) of sample 2
n2 .................................	size (positive integer) of sample 2
Save Res .....................	list for storage of calculation results (None or List 1 to 26)
Execute ........................	executes a calculation

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

20070201