20010101
o
.................................. mean of sample
x
σ
n
-1
............................. sample standard deviation (
x
σ
n
-1
>
0)
n
.................................. size of sample (positive integer)
After setting all the parameters, align the cursor with [Execute] and then press the function
key shown below to perform the calculation.
•
1
(CALC) ... Performs the calculation.
Calculation Result Output Example
Left .............................. interval lower limit (left edge)
Right ............................ interval upper limit (right edge)
o
.................................. mean of sample
x
σ
n
-1
............................. sample standard deviation
n
.................................. size of sample
u
uu
u
u
2-Sample
t
Interval
2-Sample
t
Interval
calculates the confidence interval for the difference between two
population means when both population standard deviations are unknown. The
t
interval is
applied to
t
distribution.
The following confidence interval applies when pooling is in effect. The value 100 (1 –
α
) % is
the confidence level.
Left
=
(
o
1
–
o
2
)
–
t
α
2
Right
=
(
o
1
–
o
2
)
+
t
α
2
n
1
+
n
2
–2
n
1
1 +
n
2
1
x
p
n
–1
2
σ
n
1
+
n
2
–2
n
1
1 +
n
2
1
x
p
n
–1
2
σ
x
p n
–1
=
σ
n
1
+
n
2
–
2
(
n
1
–1)
x
1
n
–1
2
+(
n
2
–1)
x
2
n
–1
2
σ
σ
1-3-9
Confidence Interval (INTR)
20011101
