How to graph a line of best fit on a TI-83 Plus

By E-Code · updated 2026-09-27

Press STAT ▶ CALC 4 to paste LinReg(ax+b), then VARS ▶ Y-VARS, ENTER, ENTER to add Y1 and ENTER to run it. Turn on 2nd STAT PLOT 1 (ENTER on On) and press ZOOM 9 (ZoomStat): the data and the line are drawn together.

Before you start

Type 1, 2, 3, 4, 5 into L1 and 2, 4, 5, 4, 5 into L2 first (STAT, ENTER), then 2nd QUIT.

Step by step

1. Open STAT. STAT Press STAT. Your data is already in L1 and L2.
2. The CALC tab. ▶ Press ▶ to CALC.
3. Pick LinReg(ax+b). 4 Press 4. It's pasted on the home screen.
4. Open VARS. VARS Press VARS, to add where the equation goes.
5. The Y-VARS tab. ▶ Press ▶ to Y-VARS: the Y= functions.
6. Pick Function. ENTER Press ENTER for Function.
7. Pick Y1. ENTER Press ENTER for Y1. The line will be stored there.
8. Calculate. ENTER Press ENTER. With no lists named, LinReg uses L1 and L2.
9. See it in Y=. Y= Press Y=. Y1 now holds the line of best fit.
10. Open STAT PLOT. 2nd Y= Press 2nd, then Y= (STAT PLOT), to show the data points too.
11. Open Plot1. 1 Press 1. Plot1 draws Xlist L1 against Ylist L2 as a scatter plot.
12. Turn it on. ENTER Press ENTER with the cursor on On.
13. Open ZOOM. ZOOM Press ZOOM. Item 9 is ZoomStat.
14. ZoomStat. 9 Press 9. ZoomStat sets a window that fits all your data, then draws.
15. Data and line together. The dots are your data and the line is y = .6x + 2.2, running through the middle of them.

What the screen shows

The dots are your data and the line is y = .6x + 2.2, running through the middle of them.

Look for ZStandard on the screen.

Try it with the keys lit up

This guide is one of E-Code's Learn lessons. Open it on E-Code's TI-84 calculator and each key lights up in turn as you press it.

Try “Graph a line of best fit” on the TI-84 calculator

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