How to Do Linear Regression on a TI-84

Fit a line to paired data, store the model and compare it with a scatterplot.

1Enter paired x-y data

2Run LinReg(ax+b)

3Store and graph the model

Worked example

Follow the example values and compare your calculator display with the expected result shown below.

Enter paired data

In STAT → EDIT, enter x-values 1,2,3,4 in L1 and y-values 3,5,7,9 in L2. Both lists must have the same length.

Turn on a scatterplot

2nd→Y= (STAT PLOT)→Plot1→On

Select the scatterplot icon, set Xlist to L1 and Ylist to L2, then use ZOOM → 9:ZoomStat.

Calculate and store the regression

STAT→CALC→LinReg(ax+b)

Specify L1, L2 and Y1. To paste Y1 into the command, use VARS → Y-VARS → Function → Y1, then press ENTER.

LinReg
 y = ax + b
 a = 2
 b = 1

Expected model: y = 2x + 1.

Interpret the model

The slope 2 means y increases by 2 for each increase of 1 in x. The intercept 1 is the model's predicted y-value when x = 0.

r and r² missing? Turn diagnostics on through the catalog command DiagnosticOn, then run the regression again.

Practice

Use x = 1,2,3 and y = 4,7,10. Predict the fitted equation.

Reveal the answer

The points lie on y = 3x + 1.

Practice with the calculator open

Use the guide in one tab and the calculator in another.

Open TI-84 Calculator

Editorial note: This guide is independently written for classroom practice and was reviewed against the TI-84 Plus CE guidebook. Button labels and menu availability can vary by model and operating-system version.

Last reviewed: July 17, 2026

Learning standard: worked example, expected result, troubleshooting and practice.

Linear Regression on a TI-84