How do I do 1-Var Stats on a TI-84?

Enter data in L1 via STAT → Edit, then press STAT → CALC → 1:1-Var Stats → ENTER. You get mean, standard deviation, five-number summary, and sample size.

How do I do linear regression (LinReg) on a TI-84?

Put x-values in L1 and y-values in L2, then press STAT → CALC → 4:LinReg(ax+b) → Calculate. The output gives the slope a, intercept b, and correlation coefficient.

Why do I not see r on my LinReg output?

Diagnostics are off. Press 2nd + 0 (CATALOG), find DiagnosticOn, press ENTER twice, then re-run LinReg. The r and r² values will appear.

How do I make a scatter plot on a TI-84?

Press 2nd + Y= (STAT PLOT), enable Plot1, choose the scatter-plot type, set Xlist to L1 and Ylist to L2, then press ZOOM → 9:ZoomStat to auto-frame your data.

How do I clear lists on a TI-84?

In the STAT list editor, arrow up to highlight the list name (L1), press CLEAR, then ENTER. The whole column empties at once.

What is the difference between LinReg(ax+b) and LinReg(a+bx)?

Just notation. LinReg(ax+b) writes the line as y = ax + b (slope first), which matches most textbooks. The math is identical — pick the form your class uses.

Can I do statistics on a free online calculator?

Our free TI-84 emulator handles standard and scientific calculations in your browser. For full list-based statistics like LinReg, the physical TI-84 (or TI software) is still the most faithful tool — this guide teaches the exact keystrokes.

TI-84 Statistics & Regression

Data in, answers out. The full AP Stats workflow.

Statistics on the TI-84 is one of its best features — once you know the STAT menu. This guide covers data entry, 1-Var Stats, LinReg, and scatter plots.

The six-step workflow

1Enter your data into lists
Press STAT, choose 1:Edit, and type your x-values into L1 (press ENTER after each). Type matching y-values into L2. If old data is in the way, arrow up to L1, press CLEAR, then ENTER.
2Run 1-Var Stats for a single list
Press STAT, arrow to CALC, choose 1:1-Var Stats, and press ENTER (twice if it asks for a list — just confirm L1). You get the mean, standard deviation, min, max, and quartiles instantly.
3Run LinReg for two lists
Press STAT → CALC → 4:LinReg(ax+b). Confirm Xlist is L1 and Ylist is L2, arrow to Calculate, and press ENTER. The calculator returns the regression line y = ax + b plus the correlation coefficient.
4Turn on diagnostics for r and r²
If you do not see the correlation coefficient, press 2nd + 0 (CATALOG), scroll to DiagnosticOn, and press ENTER twice. Run LinReg again — r and r-squared will now appear.
5Draw the scatter plot
Press 2nd + Y= (STAT PLOT), choose Plot1, turn it ON, set the type to the scatter-plot icon, and confirm Xlist L1 and Ylist L2. Then press ZOOM → 9:ZoomStat to frame the data.
6Graph the regression line over your data
After running LinReg, press Y=, then paste the equation: press VARS → 5:Statistics → EQ → 1:RegEQ. Press GRAPH to see the line of best fit drawn through your scatter plot.

Reading your LinReg output

After LinReg(ax+b), three numbers matter most. a is the slope — how much y changes per unit of x. b is the y-intercept — where the line crosses the y-axis.

r is the correlation coefficient, from −1 to 1. Near ±1 means a strong linear relationship; near 0 means the points are scattered. r² tells you what fraction of the variation your line explains — teachers love asking about this one.

Common mistakes

Forgetting DiagnosticOn

If r never appears, diagnostics are off — see step 4. This trips up nearly everyone once. Turn it on at the start of the school year and forget about it.

Mismatched list lengths

L1 and L2 must have the same number of entries for LinReg. One extra value in either list gives a DIM MISMATCH error. Count both columns before running the calculation.

Scatter plot shows nothing

Plot1 is probably off, or the window is wrong. Re-check STAT PLOT settings, then use ZOOM → 9:ZoomStat — it frames your data automatically and fixes 90% of blank-plot panic.

Keep practicing

Statistics is a button-sequence skill — repetition is everything. Drill the STAT → CALC path until you can do it without thinking. For graphing practice, our graphing guide and free graphing calculator cover the visual side.

Frequently asked questions

Last updated: September 26, 2026