Use Linear Regression in SAT Testing Desmos

For this original example, enter x subscript one equals the list one, two, three, four. On the next line enter y subscript one equals five, seven, nine, eleven. Type y subscript one, then press the right arrow to leave the subscript. Enter tilde m x subscript one, press the right arrow again, and add b. The tilde asks Desmos to fit a model to paired data. An equals sign does not perform this regression.

The regression parameters show m equals two and b equals three. Plot the ordered-pair lists x subscript one, y subscript one to see the four data points. Their y values increase by two each time x increases by one. Substituting the first point into y equals two x plus b gives b equals three. Here every point lies exactly on y equals two x plus three, so R squared equals one. Real data may have residuals. A fitted relationship does not establish causation or justify extrapolation beyond the studied range.

The points (1, 5), (2, 7), (3, 9), (4, 11) all satisfy y = 2x + 3. Slope = (11 − 5)/(4 − 1) = 2 and intercept = 5 − 2(1) = 3. Perfect fit describes only these example points.

Try the points (1, 4), (2, 7), (3, 10), (4, 13). Predict m = 3 and b = 1, then verify with regression and substitution. For noisy data, inspect residuals and the context before using a prediction.

For this original example, enter x subscript one equals the list one, two, three, four. On the next line enter y subscript one equals five, seven, nine, eleven. Type y subscript one, then press the right arrow to leave the subscript. Enter tilde m x subscript one, press the right arrow again, and add b. The tilde asks Desmos to fit a model to paired data. An equals sign does not perform this regression.

The regression parameters show m equals two and b equals three. Plot the ordered-pair lists x subscript one, y subscript one to see the four data points. Their y values increase by two each time x increases by one. Substituting the first point into y equals two x plus b gives b equals three. Here every point lies exactly on y equals two x plus three, so R squared equals one. Real data may have residuals. A fitted relationship does not establish causation or justify extrapolation beyond the studied range.

The video presents actual calculator screen captures with Google-generated narration. It is a narrated sequence of captured steps. Captures were checked on October 13, 2026 in the College Board testing configuration. Captions are timed by the measured narration segments; sentence timings within a segment are approximate. Desmos and College Board do not endorse PeakSAT.