TI-83 Instructions

Confidence Intervals for the Mean using a Small Sample

from a Normal Population

**Method
1 - Data**

** **

- Enter the sample data
into a list, say L
_{1}. - Press STAT. The STAT menus appear and the EDIT menu title is
highlighted.
- Select the TESTS menu title. The TESTS menu appears.
- Select TInterval, the 8
^{th}item. A list of options appears. - On the first line are
two options: Data and Stats. Use the arrow keys to select Data.
- Press ENTER.
- Press the down arrow
once.
- Enter the name of the
list that contains the data.
- Press the down arrow
twice (skip over the Freq option).
- Enter the confidence
level as a decimal, not a percent.
- Press the down arrow
once. The word Calculate begins to flash.
- Press ENTER. The confidence interval, in interval
notation, along with the sample mean, sample standard deviation, and
sample size, appears.

**Method
2 - Statistics**

- Follow Steps 1 – 4 in
Method 1 above.
- Use the arrow keys to
select the Stats option.
- Press ENTER.
- Press the down arrow
once.
- Enter the mean of the
sample.
- Press the down arrow
once.
- Enter the standard
deviation of the sample.
- Press the down arrow
once.
- Enter the sample size.
- Press the down arrow
once.
- Follow Steps 10 – 12 in
Method 1 above. The confidence
will appear along with the sample mean, sample standard deviation, and the
sample size.