Desmos Tricks
R-Squared Check
Compare multiple models to find the best fit.
🎯 The R² Check
Closer to 1 means better fit. Use to choose between Linear/Quadratic.
R² = 0.998
📝 SAT Problem
Which regression model best fits the data provided below?
| x | y |
|---|---|
| 1 | 2.1 |
| 2 | 3.9 |
| 3 | 8.2 |
| 4 | 14.1 |
| 5 | 22.0 |
(A) Linear
(B) Quadratic
(C) Exponential
(D) None
Step 1: Enter the Data
Click + > Table. Type the x and y values from the problem.
Step 2: Test Linear vs Quadratic
Type y1 ~ mx1 + b. Check \(R^2\). (Values will be low, \( \approx 0.96
\))
Type y1 ~ ax1^2 + bx1 + c. Check \(R^2\). (Values will be \( \approx
0.999 \))
Step 3: Conclusion
The Quadratic model has an \(R^2\) much closer to 1.
✅ Final Answer: (B)