Mean and Standard Deviation on a TI-82 or TI-83


Here's how to compute some basic statistics on your TI-82. The TI-83 works almost exactly the same. TI-83 differences are summarized here.

  1. Press the [STAT] button. You should see this on your screen: 
  2. Notice that EDIT and 1: are highlighted. Press [1] or just [ENTER] to indicate you want to edit (i.e. enter) a list of numbers. Now your screen should look something like:   or: 
  3. If there is a list of numbers in the first column, as in the first picture above, press [DEL] until the column is empty, as in the second picture above.
  4. Now type in your list of numbers, pressing [ENTER]after each one. For instance, if your list of numbers is {1,3,4,5,7}, then when you are done, your screen should look like the first picture in step #2 above. [Note: You do not have to enter the numbers in order]
    1. Check over your list and make sure you have typed it correctly. You can delete entries with the [DEL] key, or insert entries by using the [2nd][INS] keys. Note: To type [2nd][INS], press the [2nd] key, then find INS above the [DEL] key, and press that key.
  5. Press the [STAT] button again, so that you are back to: 
  6. Press the   key to highlight the CALC heading, and the screen changes to: 
  7. Notice that CALC and 1: are highlighted. Press [1] or just [ENTER] to indicate you want to calculate some one-variable statistics for your list. The screen now looks like: 
  8. Now tell the calculator what list you put your numbers in. Normally this will be the list L1, but use whatever list you typed your numbers under in step #4. To type L1, press [2nd][L1]   (L1 is over the [1] button). You should now see: 
  9. Press [ENTER]to do the computation: 

  10. The =4 tells you the mean of your list is 4. The x=2 tells you the [population] standard deviation of your list is 2.

Short summary:

Press [STAT] and select EDIT to enter your list of numbers. Remember the list you entered them in (watch the heading over your number on the calculator screen). Press [STAT] and select CALC, then select 1-Var Stats. Enter the name of the list you used, and press [ENTER] to view the results.

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.

Bonus Topics:

Frequency tables:

If you have many repeated data items, such as a frequency table:
 
data item frequency
8

...meaning that your list contains four 3's, five 8's, etc., then you can enter two lists of data (preferably in L1 and L2) as shown:

Then ask the calculator to calculate 1-variable statistics for L1 and L2 as shown: 

Help with medians:

Once you type a list of numbers into a column in the list editor (see steps #1- #4 above), you can press [STAT] again, select SortA(, indicate L1 (or whatever list you put your numbers in) and press enter: . Then when you edit the list again, you will find the list is displayed in ascending order, making it easier to pick out the median.

TI-83 differences

First, several of the menus have additional options on the '83.
Second, the right-arrow button is curved and blue :)
Finally, the only important difference: If you do one-variable statistics and scroll down a bit on the results, you get a few bonuses - try it!

Last Modified February 2, 1999.
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