Casio fx-9750G PLUS - Manual (Page 329)

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.jfw
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