Mean and Standard Deviation on a Basic Scientific Calculator
Note: This page is NOT relevant for graphing calculators like the TI81,
TI82, TI83, or TI85.
Here's how to compute some basic statistics on a basic scientific calculator:
Background:
First, figure out if your calculator requires you to set it in "STAT
MODE". The SHARPbrand calculators I've seen do, and some
of
the TI calculators do too. Look to see if you have a MODE
button. The T.I.'s with a "STAT 1" button require this also.
IF YOU HAVE A MODEBASED calculator, as described above:
Figure out how to get stat mode.

On the Sharp calculators, try [MODE][1].
Look for a tiny word "STAT" displayed on your screen. If [1]
doesn't work, try other numbers. As an absolutely last resort (I'm joking),
look in your calculator manual under "statistics".

On the TI calculators, try either [MODE][STAT]or
[2nd][STAT
1] or [3rd][STAT 1] until a tiny "STAT"
is displayed on your screen.
Entering Data:
You may need to clear out old data first. Look for a [CA] button
(on Sharps) or [CSR] (for clear statistics registers) on TIs.
Once you have set the mode (if needed), enter data as described in the
next paragraph. If you aren't sure about needing to set the mode, see if
the following works without setting a mode.
One at a time, type a number in your list of data, and then press the
dataentry button. On the TI calculators, the dataentry button looks like
this: [+].
On the Sharp calculators, the dataentry button may have [M+]
on it, or it might say "DATA".
So for example, if your list was 3,5,4,7,1, then on the TI, you would
type 3[+]5[+]4[+]7[+]1[+].
On the Sharp, you would type 3[M+]5[M+]4[M+]7[M+]1[M+].
On both calculators, each time you enter a datum (unit of data),
the calculator shows the count of the data entered so far. So if you've
done the keystrokes above, your calculator should show "5" (or
maybe "n=5"). You have now successfully entered your data.
Making calculations:
This part is easy. Once you have entered your data, to find the mean or
average, find an
button and press it. The mean is displayed.
To find the standard deviation, find a button marked [x]
or [n]
or [xn]
or just [].
Press that and the standard deviation is displayed.
Watch out, don't press [y]
or [n1]
or [xn1]
or just [s]. These are related to the standard deviation, but
they aren't what we want.
Short summary:
Enter STAT mode if your calculator requires it. Clear the any
old data if necessary. Enter the data one at a time using a [+]
or [M+] button. Press an
button to get the average or mean, press [x]
to get the S.D. (make sure you use the correct []
button for your calculator.
Test yourself:
Try to get the mean and standard deviation of 37.75, 38, 37,
38.5, and 37.5. You should get a mean of 37.75 and a standard deviation
of 0.5.
Last Modified January 31, 2000.
Prof.
Janeba's Home Page  Send comments or questions to: mjanebawillamette.edu
Department
of Mathematics  Willamette
University Home Page