Casio fx-9860G AU - Page 339

20050401
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)
o .................................. mean of sample
x σ n-1 ............................. sample standard deviation
(Displayed only for Data: List setting.)
n .................................. size of sample
uu
uu
u 2-Sample Z Interval
2-Sample Z 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 = (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
o1 :mean of sample 1
o2 :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)
6-6-4
Confidence Interval