20070201
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 ..............................confi dence interval lower limit (left edge)
Right ............................confi dence interval upper limit (right edge)
¯x .................................. mean of sample
x
σ
n-1 .............................sample standard deviation
(Displayed only for Data: List setting.)
n ..................................size of sample
u 2-Sample Z Interval
2-Sample Z Interval calculates the confi dence interval for the difference between two
population means when the population standard deviations of two samples are known.
The following is the confi dence interval.
α is the level of signifi cance. The value 100 (1 – α)
% is the confi dence level.
¯x1 : mean of sample 1
¯x2 : mean of sample 2
σ
1 : population standard deviation
of sample 1
σ
2 : 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)
Left = (o
1
– o
2
) – Z
α
2
Right = (o
1
– o
2
) + Z
α
2
n
1
1
2
σ
+
n
2
2
2
σ
n
1
1
2
σ
+
n
2
2
2
σ
Left = (o
1
– o
2
) – Z
α
2
Right = (o
1
– o
2
) + Z
α
2
n
1
1
2
σ
+
n
2
2
2
σ
n
1
1
2
σ
+
n
2
2
2
σ
6-6-4
Confi dence Interval
