Calculating mean and standard deviation on the Casio fx-9700GE:

Let's say we have a table of data describing four birds of different species (units of height and weight have been left out here):
 


height
weight
2
5
3
6
1
5
4
5
You can think of the two columns as representing variables x and y.

First we have to enter the data. Hit the MENU button until you get to the "main menu". Select SD by moving the cursor to that option (using the up-down-right-left keys) and hitting EXE.
 
On some Casio models SD is called "STAT" instead.

The resulting screen shows several options at the bottom, including EDIT and DEV. Select EDIT (F2). (on some models this option is abbreviated CAL instead of EDIT.)

Now you will see a table with the headings x and f. Let's say we wanted to find the mean and standard deviation of the data in the first column. We would enter values in the table as follows:

x
 f
2
1
3
1
1
1
4
1

This is a "frequency table" for the x-values. If you need to clear a pre-existing table first, use "erase" (ERS-- F3). This model requires that you enter the data one complete row at a time.

Hit MENU and then SD (or STAT) to get back to the previous screen, then select DEV (F4). Then pick the mean or   xs n-1  then EXE to get the appropriate statistic.

You may then repeat the process using the y data in the 1st column instead.

Some models will allow you to enter both columns of data in the same table, as it appears at the top of this page.