Probability and Statistics > TI 89 > Variance TI-89

While performing variance and standard deviation calculations by hand can be time consuming and tedious, the TI-89 can help you perform these calculations in seconds. **Finding a variance** on a TI-89 is as simple as entering a few numbers and hitting a couple of keys. These instructions are for the TI-89 Titanium or the regular TI-89.

## Variance TI-89: Steps

Watch the video or read the article below:

**Sample problem:** Find the Variance for the following data set: 2, 4, 5, 6, 8, 10, 15, 23.

**Step 1:** Press the HOME key. The home key is on the left hand side, third button from the top.

**Step 2:** Press the CATALOG key

It’s located below the APPS key in the top middle of your keypad.

**Step 3:** Press the down arrow key to scroll to **variance(**. Press the ENTER key.

*A quicker way*: once you get into the catalog, type the letter v (using the ALPHA key) to take you to the beginning of the v list.

**Step 4:** Press the 2ND key and then the open parenthesis key “(“. If you did this correctly, you should have a curly bracket. The following should now be showing on your screen:

**variance({**

**Step 5:** Enter your data set. Each number should be followed by a comma.

In our example, enter:

2, 4, 5, 6, 8, 10, 15, 23.

So you get: **variance({2,4,5,6,8,10,15,23**

**Step 6:** Press, the 2ND button, then the close parenthesis button twice. These keystrokes close the expression so you have:

**variance({2,4,5,6,8,10,15,23})**. (**Important!** Your expression must look exactly like this, with both sets of parentheses and curly parentheses.)

**Step 7:** Press ENTER.

**Step 8:** Press The diamond (♦) key and then press ENTER to get a decimal answer if the calculator gives you a radical or fractional expression (and it probably will).

That’s how to find variance TI-89! The variance for the data set {2,4,5,6,8,10,15,23} is displayed, which is **47.5536**.

Lost your guidebook? You can download a new one from the TI website here.

If you prefer an online interactive environment to learn R and statistics, this free R Tutorial by Datacamp is a great way to get started. If you're are somewhat comfortable with R and are interested in going deeper into Statistics, try this Statistics with R track.

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