Cubic Regression Eb0072
1. **Problem Statement:** Given the data points $(x, y)$:
$$
\begin{array}{c|c}
x & y \\\hline
-4 & -33 \\
-3 & 21 \\
-2 & 15 \\
-1 & -20 \\
0 & 7 \\
1 & -5 \\
2 & 20 \\
3 & -20 \\
4 & 15 \\
5 & 21 \\
6 & -33 \\
\end{array}
$$
We need to determine which type of regression best fits this data: linear, quadratic, cubic, or none.
2. **Understanding Regression Types:**
- Linear regression fits data to a line: $y = ax + b$.
- Quadratic regression fits data to a parabola: $y = ax^2 + bx + c$.
- Cubic regression fits data to a cubic curve: $y = ax^3 + bx^2 + cx + d$.
3. **Analyzing the Data:**
- The data shows symmetry and multiple peaks and troughs.
- Linear regression is unlikely because the data is not a straight line.
- Quadratic regression typically has one peak or trough; here, there are multiple.
- Cubic regression can model multiple turning points, matching the data's behavior.
4. **Conclusion:**
The data's pattern with multiple peaks and troughs suggests a cubic regression is the best fit.
**Final answer:** C) Cubic Regression