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

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416
t
=
(
x – m
)
x
n
–
1
n
Program for
t -Test Value
Description
The mean (sample mean) and sample standard deviation can be used to obtain a
t
-test
value.
x
: mean of
x
data
x
σ
n
–1
: sample standard deviation of
x
data
n
: number of data items
m
: hypothetical population standard deviation (normally
represented by
µ
, but
m
is used here because of variable
name limitations)
Example
To determine whether the population standard deviation for sample data 55, 54, 51,
55, 53, 53, 54, 52, is 53.
Perform a
t
-test with a level of significance of 5%.
Preparation and operation
• Store the program written on the next page.
• Execute the program as shown below.
No.
3
Step Key operation Display Step Key operation Display
The above operation produces a
t
-test value of
t
(53) = 0.7533708035. According to the
t
-distribution
table in the next page, a level of significance of 5% and a degree of freedom of 7 (
n
– 1 = 8 – 1 = 7)
produce a two-sided
t
-test value of approximately 2.365. Since the calculated
t
-test value is lower
than the table value, the hypothesis that population mean
m
equals 53 is accepted.
PROGRAM SHEET