Casio CFX-9850G PLUS, User'S Manual & Technical Reference

Page: 329 / 486

301
Example To calculate the 1-Sample
t
Interval for one list of data
For this example, we will obtain the 1-Sample
t
Interval for data
= {11.2, 10.9, 12.5, 11.3, 11.7} when C-Level = 0.95.
1
(List)
c
a.jf w
1
(List1)
c
1
(1)
c
1
(CALC)
Left ................. interval lower limit (left edge)
Right ............... interval upper limit (right edge)
o ..................... sample mean
x σ
n -1
................ sample standard deviation
n
..................... sample size
u u u 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
The following confidence interval applies when pooling is not in effect.
The value 100 (1 –
α
) % is the confidence level.
Left =
(
o
1
–
o
2
)–
t
df
α
2
Right =
(
o
1
–
o
2
)+
t
df
α
2
+
n
1
x
1
n
–1
2
σ
n
2
x
2
n
–1
2
σ
+
n
1
x
1 n –1
2
σ
n
2
x
2 n –1
2
σ
C
=
df =
1
C
2
n
1
–1
+
(1– C )
2
n
2
–1
+
n
1
x
1 n –1
2
σ
n
1
x
1
n
–1
2
σ
n
2
x
2
n
–1
2
σ
Confidence Interval
18 - 7
x
p n –1
=
σ
n
1
+
n
2
– 2
(
n
1
–1)
x
1 n –12
+(
n
2
–1)
x
2 n –12
σ σ