Mean and standard deviation on the TI-82

Calculating mean, variance and standard deviation on the TI-82:

1. Press STAT. Move the cursor to "Edit" (it may already be there) and then press ENTER.

2. Clear any data already in the table. Then type your data values into the first column, using the 4 directional keys to move around the table.

3. Press STAT again, but this time select "Calc" and then "1-var statistics." The screen displays the mean (x bar), the standard deviation (s, shown here as s_x), and the number of data points (n, also known as the sample size).

* The variance is obtained by squaring the standard deviation.

*The calculator also shows sigma_x, which is what the s.d. would be if we used n instead of n-1.