The following estimated regression equation is based on 30 observations. The values of SST and SSR are 1,801 and 1,762, respectively. a. Compute R² (to 3 decimals). b. Compute R (to 3 decimals). c. Comment on the goodness of fit. The estimated regression equation provided an excellent fit Hide Feedback Partially Correct Icon Key ŷ 18.1 +3.9x12.1x2 + 7.8x3 +2.8x4 Hint(s) Che Hint(s) Che

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
### Regression Analysis Example

**Problem Statement:**
The following estimated regression equation is based on 30 observations.

\[
\hat{y} = 18.1 + 3.9x_1 - 2.1x_2 + 7.8x_3 + 2.8x_4
\]

The values of SST (Total Sum of Squares) and SSR (Sum of Squares for Regression) are 1,801 and 1,762, respectively.

**Tasks:**

a. **Compute \(R^2\) (to 3 decimals).**

b. **Compute \(R^2_{\text{adj}}\) (to 3 decimals).**

c. **Comment on the goodness of fit.**

**Solution:**

a. To compute \(R^2\):

\[
R^2 = \frac{\text{SSR}}{\text{SST}} = \frac{1,762}{1,801} \approx 0.978
\]

Incorrect entry: 

\[ \]

b. To compute \(R^2_{\text{adj}}\):

\[
R^2_{\text{adj}} = 1 - \left(\frac{1 - R^2}{n - k - 1} \times (n - 1)\right) 
\]

Where:
- \( n \) is the number of observations (30)
- \( k \) is the number of predictors (4)

So,

\[
R^2_{\text{adj}} = 1 - \left(\frac{1 - 0.978}{30 - 4 - 1} \times (30 - 1)\right) 
\]

Incorrect entry: 

\[ \]

c. Comment on the goodness of fit:
The estimated regression equation provided an excellent fit.

Correct selection: 
\[
\boxed{\text{provided an excellent fit}}
\]

Explanation: 

- **Hint:** Use the provided results and formulas for calculating the coefficients of determination to evaluate the regression model.
- **Feedback:** Partially correct. Ensure the correct values are entered for theoretical completeness.

**Graph/Diagram Explanation:**

No graphs or diagrams are present in this example.

---

This form of transcription can serve as an understanding aid for students studying regression analysis, helping them to correctly apply and interpret the formulas involved. This example elucidates the process of computing both \(R^2\) and \(R
Transcribed Image Text:### Regression Analysis Example **Problem Statement:** The following estimated regression equation is based on 30 observations. \[ \hat{y} = 18.1 + 3.9x_1 - 2.1x_2 + 7.8x_3 + 2.8x_4 \] The values of SST (Total Sum of Squares) and SSR (Sum of Squares for Regression) are 1,801 and 1,762, respectively. **Tasks:** a. **Compute \(R^2\) (to 3 decimals).** b. **Compute \(R^2_{\text{adj}}\) (to 3 decimals).** c. **Comment on the goodness of fit.** **Solution:** a. To compute \(R^2\): \[ R^2 = \frac{\text{SSR}}{\text{SST}} = \frac{1,762}{1,801} \approx 0.978 \] Incorrect entry: \[ \] b. To compute \(R^2_{\text{adj}}\): \[ R^2_{\text{adj}} = 1 - \left(\frac{1 - R^2}{n - k - 1} \times (n - 1)\right) \] Where: - \( n \) is the number of observations (30) - \( k \) is the number of predictors (4) So, \[ R^2_{\text{adj}} = 1 - \left(\frac{1 - 0.978}{30 - 4 - 1} \times (30 - 1)\right) \] Incorrect entry: \[ \] c. Comment on the goodness of fit: The estimated regression equation provided an excellent fit. Correct selection: \[ \boxed{\text{provided an excellent fit}} \] Explanation: - **Hint:** Use the provided results and formulas for calculating the coefficients of determination to evaluate the regression model. - **Feedback:** Partially correct. Ensure the correct values are entered for theoretical completeness. **Graph/Diagram Explanation:** No graphs or diagrams are present in this example. --- This form of transcription can serve as an understanding aid for students studying regression analysis, helping them to correctly apply and interpret the formulas involved. This example elucidates the process of computing both \(R^2\) and \(R
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 1 images

Blurred answer
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman