Don Kossow wrote to TI for help in calculating standard deviations on the TI-82 and received the following reply:
Example 1
=================
x values: 5, 9, 7, 4, 6, 250, 35, 100, 84
a) What is the mean?
b) What is the standard deviation?
1. Press [STAT] [ENTER] to enter the statistics list editor.
2. Enter the numbers into the list by pressing each number and [ENTER].
3. Press [STAT] [right cursor] to enter the CALC menu.
4. Select 1:1-Var Stats. 1-Var Stats will be typed on the home screen,
press [ENTER]
5. The statistics will be displayed. You can scroll through them with the
cursor keys.
For reference: The answer is mean=55.56, Sample std.dev.=81.56, Population
std.dev.=76.89
Example 2
==================
We have a group of students with the following test scores:
87
52
97
46
75
60
To find the standard deviation for the test scores, follow the directions
below:
1. Clear your screen then press [STAT] [ENTER]
2. Highlight L1 and press [CLEAR] [ENTER]
3. Enter the test scores under the xStat list. [ 8 ] [ 7 ] [ENTER] (and
so on) Press [STAT]
4. Highlight CALC then press [ENTER]
5. Press [2nd] [ 1 ] [ENTER]
6. Your screen will display all 1-Var Stats for List 1.
I hope you find this information helpful. If you have further questions or
comments please feel free to contact me at your convenience. Please copy
this message in your response and send directly to ti-cares@ti.com.
Sincerely,
Terri Viana
------------------------------------------------------------------------
Educational & Productivity Solutions
Customer Support Center E-mail: ti-cares@ti.com
Texas Instruments
PO Box 650311 M/S 3962
Dallas, TX 75265 (972)917-8324 (Technical Help)
(800) 842-2737 (General Info)
(972)917-0747 (Fax)