Math Problem Statement

  SUMMARY OUTPUT     Regression Statistics   Multiple R

0.638376   R Square

0.407524   Adjusted R Square

0.282792   Standard Error

36.95796   Observations

24     ANOVA   **  df

SS

MS

F

Significance F **  Regression

4

17850.58

4462.644

3.267204

0.033731   Residual

19

25951.92

1365.891   Total

23

43802.5           **  Coefficients

Standard Error

t Stat

P-value

Lower 95% **  Upper 95%

Lower 95.0%

Upper 95.0%

Intercept

1794.919

515.5536

3.481537

0.002498

715.8528   2873.985

715.8528

2873.985

Price

-0.02985

0.436333

-0.06841

0.946176

-0.9431   0.883407

-0.9431

0.883407

Time-Free

-5.82049

4.861381

-1.19729

0.245918

-15.9955   4.354497

-15.9955

4.354497

Income

-0.56466

0.204485

-2.76136

0.012425

-0.99265   -0.13666

-0.99265

-0.13666

South Bay

-0.09388

0.193664

-0.48477

0.633378

-0.49923   0.311461

-0.49923

0.311461

Solution

This output is from a multiple linear regression analysis. Let’s break it down in sections:

1. Regression Statistics

  • Multiple R (0.638376): This is the correlation coefficient, showing the strength of the relationship between the dependent variable and the independent variables. A value of 0.638 means a moderate positive correlation.
  • R Square (0.407524): This indicates that about 40.75% of the variability in the dependent variable is explained by the model.
  • Adjusted R Square (0.282792): This is adjusted for the number of predictors in the model, providing a more accurate estimate when dealing with multiple independent variables. It suggests a weaker fit than R² (28.28% of the variance explained).
  • Standard Error (36.95796): This measures the average distance that the observed values fall from the regression line.
  • Observations (24): The number of data points (24 observations) used in the regression.

2. ANOVA (Analysis of Variance)

  • df (degrees of freedom):
    • Regression df = 4, corresponding to the number of predictors.
    • Residual df = 19, corresponding to the number of observations minus the number of predictors and the intercept.
    • Total df = 23, the total number of observations minus 1.
  • SS (Sum of Squares):
    • Regression SS = 17850.58, representing the explained variability.
    • Residual SS = 25951.92, representing the unexplained variability.
    • Total SS = 43802.5, the total variability.
  • MS (Mean Square):
    • Regression MS = 4462.644 (Regression SS / Regression df).
    • Residual MS = 1365.891 (Residual SS / Residual df).
  • F-statistic (3.267204): This tests the overall significance of the model. A higher F-statistic indicates that the model is significant. The significance F value (p-value) is 0.033731, which is less than 0.05, indicating the model is statistically significant.

3. Coefficients

Each independent variable has an associated coefficient, standard error, t-statistic, and p-value. These values tell us about the influence of each variable on the dependent variable:

  • Intercept (1794.919): This is the expected value of the dependent variable when all predictors are 0.
    • P-value (0.002498): This is significant (p < 0.05), indicating the intercept is statistically meaningful.
  • Price (-0.02985): Suggests that for each unit increase in Price, the dependent variable decreases by 0.02985, although the p-value (0.946176) shows this is not statistically significant.
  • Time-Free (-5.82049): Suggests a negative relationship, but it is not statistically significant (p = 0.245918).
  • Income (-0.56466): Suggests a significant negative relationship (p = 0.012425), meaning Income has a meaningful negative impact on the dependent variable.
  • South Bay (-0.09388): Suggests a small negative relationship, but it is not statistically significant (p = 0.633378).

Conclusion:

  • The model explains 40.75% of the variability in the dependent variable.
  • The overall model is statistically significant (p-value of 0.033731).
  • Of the predictors, only Income has a statistically significant impact on the dependent variable.

Would you like to explore any details or have further questions?

Related Questions:

  1. How do we interpret a high p-value for a coefficient in regression analysis?
  2. What is the significance of the F-statistic in this regression model?
  3. Can you explain the difference between R-Square and Adjusted R-Square?
  4. How does the standard error affect the confidence intervals of the coefficients?
  5. What does it mean when a coefficient is not statistically significant but the model is?

Tip:

Always check the p-values of individual predictors to understand which variables significantly contribute to the model.

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Math Problem Analysis

Mathematical Concepts

Regression Analysis
ANOVA
Statistical Significance
Linear Relationships

Formulas

Multiple R: Correlation Coefficient
R-Square = 1 - (SS_res / SS_total)
Adjusted R-Square = 1 - [(1 - R^2) * (n-1) / (n - p - 1)]
F-statistic = MS_regression / MS_residual

Theorems

Least Squares Method
Statistical Hypothesis Testing
P-value Interpretation

Suitable Grade Level

College Statistics