These calculators cover the statistics you do on a TI-84 in AP Statistics and intro college courses. Each one gives you the answer right away and the exact buttons to press, so you can check homework and learn the handheld at the same time.
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Standard Deviation Calculator (TI-84 Method)
Sample and population standard deviation from a list, with Sx and σx explained.
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Mean, Median, and Mode Calculator (TI-84)
Center of a data set, quartiles, and how to find the mode the TI-84 does not show.
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Z-Score Calculator
How far a value sits from the mean, and its normal probability with normalcdf.
How the TI-84 STAT menu is organized
Statistics on a TI-84 lives in three menus. STAT holds your data and the main calculations, LIST works on whole lists, and DISTR handles probability.
| Menu | How to open it | What is inside |
|---|---|---|
| STAT EDIT | STAT | The list editor for L1 to L6, SortA(, SortD(, and ClrList |
| STAT CALC | STAT, right arrow | 1-Var Stats, 2-Var Stats, and the regressions such as LinReg(ax+b) |
| STAT TESTS | STAT, right arrow twice | Hypothesis tests and confidence intervals such as Z-Test and TInterval |
| LIST | 2nd STAT | OPS for sorting and building lists, MATH for mean(, median(, and stdDev( |
| DISTR | 2nd VARS | normalcdf(, invNorm(, binompdf(, tcdf(, and other distributions |
Almost every problem follows the same path. Enter the data in STAT EDIT, run a command from STAT CALC, then use DISTR or STAT TESTS for the probability or the test.
On a TI-84 Plus CE with a recent operating system, most of these commands open a short input screen before they run. Fill in each line, such as List and FreqList for 1-Var Stats, then select Calculate or Paste. Older models paste the command onto the home screen instead, and you type the arguments yourself.
Which calculator do I need?
Match your question to the tool. For probability questions, the DISTR menu on the free TI-84 calculator online has normalcdf, binompdf, and the rest.
| Your question | Use this |
|---|---|
| How spread out is my data? | Standard deviation |
| What is a typical value? | Mean, median, and mode |
| How unusual is one value? | Z-score |
| What share of values falls below a cutoff? | Z-score, then normalcdf |
TI-84 symbols and what your textbook calls them
The TI-84 screen uses short labels that do not always match your textbook. This table lines them up so you copy the right number onto your paper.
| On the TI-84 | In your textbook | Meaning |
|---|---|---|
| x̄ | x̄ | Sample mean |
| Sx | s | Sample standard deviation |
| σx | σ | Population standard deviation |
| n | n | Number of values |
| Med | M or Q2 | Median |
| Q1 and Q3 | Q1 and Q3 | First and third quartiles |
When a free response question asks you to show work, write the textbook symbol and the value, not the calculator label. Writing s = 2.14 earns the point, while copying "Sx" with no context may not.
Before you run any statistics command
Most wrong answers on a TI-84 come from the data, not the math. Three checks catch nearly all of them.
- Clear old data first. Press STAT, 4 for ClrList, then 2nd 1 and ENTER to empty L1.
- Check n on the 1-Var Stats screen. If it does not match your count, the list has extra values. List errors are explained in the TI-84 error codes guide.
- Leave FreqList blank unless your problem gives frequencies. An old list there changes every result.
To practice the full sequence with real keys, use the free TI-84 calculator online. It has the list editor, 1-Var Stats, and the DISTR menu, and it saves your lists between visits.