Texas Instruments TI-84 PLUS - Graphing Calculator Manual Book page 223

4. Press ... | to display the
and then press † until
5. Press Í to select
stat editor for
TInterval
, press | Í to select
selected for
Inpt:
Press † y 9 and press † until
highlighted and then press Í.
Press † † Ë
to enter a 99 percent confidence
99
level at the
C-Level:
6. Press † to move the cursor onto
then press Í. The confidence interval is
calculated, and the
on the home screen.
Interpreting the results
The first line, (
159.74,173.94
mean is between about 159.74 centimeters and 173.94 centimeters. This is about a 14.2
centimeters spread.
The .99 confidence level indicates that in a very large number of samples, we expect 99 percent of
the intervals calculated to contain the population mean. The actual mean of the population
sampled is 165.1 centimeters, which is in the calculated interval.
The second line gives the mean height of the sample v used to compute this interval. The third line
gives the sample standard deviation
To obtain a more precise bound on the population mean m of women's heights, increase the
sample size to 90. Use a sample mean v of 163.8 and sample standard deviation
calculated from the larger random sample. This time, use the
option.
1. Press ... |
to display the inferential stat
8
editor for
TInterval
Press ~ Í to select
changes so that you can enter summary statistics
as input.
STAT TESTS
is highlighted.
8:TInterval
. The inferential
8:TInterval
is displayed. If
Data
HGHT
prompt.
Calculate
results are displayed
TInterval
), shows that the 99 percent confidence interval for the population
. The bottom line gives the sample size
Sx
.
. The editor
Inpt:Stats
Chapter 13: Inferential Statistics and Distributions
menu,
is not
.
Data
is
, and
(summary statistics) input
Stats
.
n
of 7.1
Sx
216