177
Chapter 8: Statistics & Regression Calculations
13 Zint2samp Finds the confidence bound of two sample means
µ
1
and
µ
2
.
Example
Find the confidence interval of
µ
1
and
µ
2
of sample data with the
confidence level of 0.9, where x
_
1
= 77.3,
s
1
= 3.4, n
1
= 30 and x
_
2
= 75.2,
s
2
= 2.8, n
2
= 20 (x
_
1
and x
_
2
indicate sample means of two
data.)
Set the input method to value input mode
1. Press
#
S
E
1
7
E
.
2. Press
S
E
1
3
.
Parameter input screen will appear.
3. Enter the appropriate value
into each field.
4. Press
@
h
.
Answers will be displayed
on the screen, where the
numeric value within ()
indicates the confidence
interval of
µ
1
and
µ
2
at a confidence level of 90%.
* n
1
and n
2
are positive integers.
14 Zint1prop Finds the confidence interval of the success probability of a
population from the success probability obtained from sample data
collected from a population.
Example
A coin was tossed 100 times and landed head side up 42 times.
Normally, the probability of head facing up is 0.5. Find the
confidence interval of the success probability at a confidence level
of 0.95.
1. Press
S
E
1
4
.
The parameter input screen will appear.
