Casio FX-9750G PLUS User's Manual & Technical Reference page 327

u u u u u 2-Prop Z Interval
2-Prop Z 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. The value 100 (1 –
level.
x – Z α
x
1
2
Left = –
n
n
1 2
+ Z α
x x
1 2
Right = –
n n
1 2
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)
x
.................... sample 1 data value (
1
n
.................... sample 1 size (positive integer)
1
x
.................... sample 2 data value (
2
n
.................... sample 2 size (positive integer)
2
Execute .......... Executes a calculation
Example To calculate the 2-Prop Z Interval using parameter value
specification
For this example, we will obtain the 2-Prop Z Interval when
C-Level = 0.95,
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1(CALC)
Left ................. interval lower limit (left edge)
Right ............... interval upper limit (right edge)
x x x
1– n 1– n
1 1 2
n n
1 1 2
+
n n
2
1
x x
x
1 1– n 1
2
n n
1 1 2
+
n
2
1
x
1
x
2
x n
= 49, = 61,
1 1
Confidence Interval
α
) % is the confidence
n n
, : sample size
1 2
x
2
x x
, : data
1 2
2
2
x
1– n 2
2
n
2
> 0)
> 0)
x n
= 38 and = 62.
2 2
18 - 7
299