Casio ClassPad II fx-CP400 - Manual (Page 144)

Chapter 7: Statistics Application 144
1-Sample Z Interval .... [Interval] - [One-Sample Z Int] Lower, Upper = o ϯ Z α
2
σ
n
Calculates the confidence interval for the population mean based on a sample mean and known population
standard deviation.
0708 To specify the data below and perform a 1-Sample Z Interval calculation
list1: {299.4, 297.7, 301, 298.9, 300.2, 297}
Population standard deviation: 3
Significance level: 5% ( = confidence level: 95%)
2-Sample Z Interval .... [Interval] - [Two-Sample Z Int] Lower, Upper = ( o
1
– o
2
) ϯ Z α
2 n
1
1
2 σ
+
n
2
2
2 σ
Calculates the confidence interval for the difference between population means based on the difference
between sample means when the population standard deviations are known.
1-Proportion Z Interval .... [Interval] - [One-Prop Z Int] Lower, Upper =
α
2
ϯ Z x
n n
1
n
x
n
x
1–
Calculates the confidence interval for the population proportion based on a single sample proportion.
2-Proportion Z Interval .... [Interval] - [Two-Prop Z Int] Lower, Upper =
Calculates the confidence interval for the difference between population
proportions based on the difference between two sample proportions.
1-Sample t Interval .... [Interval] - [One-Sample t Int] Lower, Upper = o ϯ t
n –1
α
2 n
s x
Calculates the confidence interval for the population mean based on a sample mean and a sample standard
deviation when the population standard deviation is not known.
2-Sample t Interval .... [Interval] - [Two-Sample t Int]
Calculates the confidence interval for the difference between population means based on the difference
between sample means and sample standard deviations when the population standard deviations are not
known.
 When the two population standard deviations
are equal (pooled)
Lower, Upper = o ² o ϯ W
_
Q Q ²
s S
Q Q
s
S
= (( Q
1
– 1)s
[ 1
2 + ( Q
2
– 1)s
[ 2
2 )/( Q
1
+ Q
2
– 2)
 When the two population standard deviations
are not equal (not pooled) Lower, Upper = (o
1
– o
2
) ϯ t
df
α
2
+
n
1
s
x 1
2
n
2
s
x 2
2
df = 1/(C 2 /( n
1
– 1) + (1 – C) 2 /( n
2
– 1)) C = (s
x 1
2 / n
1
)/(s
x 1
2 / n
1
+ s
x 2
2 / n
2
)
General Confidence Interval Precautions
If you input a C-Level (confidence level) value in the range of 0 s C-Level < 1, the value you input is used. To
specify a C-Level of 95%, for example, input “0.95”.
–
ϯ Z α
2
x
1
n
1
x
2
n
2
n
1
n
1
x
1 1– n
1
x
1
+
n
2
n
2
x
2 1– n
2
x
2