Applied Business Statistics Issue November 9, 2020
Hw 2applied Business Statistics Iidue November 9 2020this Assignmen
HW 2 Applied Business Statistics II Due: November 9, 2020 This assignment is about one of the most popular datasets in statistics / analytics called the Boston Housing data. The dataset contains information collected by the U.S Census Bureau related to housing in the Boston area. It’s a small dataset with only 506 cases. The main purpose is to apply simple linear regression technique using MEDV as the dependent variable: Here is the list of variables in the data: Variables list: 1. CRIM - per capita crime rate by town 2. ZN - proportion of residential land zoned for lots over 25,000 sq.ft. 3. INDUS - proportion of non-retail business acres per town. 4. CHAS - Charles River dummy variable (1 if tract bounds river; 0 otherwise) 5. NOX - nitric oxides concentration (parts per 10 million) 6. RM - average number of rooms per dwelling 7. AGE - proportion of owner-occupied units built prior to . DIS - weighted distances to five Boston employment centres 9. RAD - index of accessibility to radial highways 10. TAX - full-value property-tax rate per $10,. PTRATIO - pupil-teacher ratio by town 12. B - 1000(Bk - 0.63)^2 where Bk is the proportion of blacks by town 13. LSTAT - % lower status of the population 14. MEDV - Median value of owner-occupied homes in $1000's The instructions for this assignment are the same as last time. Remember to copy and paste the most important pieces of software output and describe in detail. You are required to write analysis report answering the following questions. Use MEDV as the dependent variable and run FIVE separate simple linear regression models by choosing the most appropriate independent variables of your liking. Compare the models by describing the salient features within each model such as R^2, MSE, parameter estimate (beta), significance of the parameter, residuals etc. Also create plots to test the accuracy of the regression model. Lastly, make sure that the MEDV variable is normally distributed to be used as the dependent variable, and if not, then transform it to normal distribution. Please write 1200 words.
Paper For Above instruction
Introduction
The Boston Housing dataset provides a comprehensive overview of factors influencing housing prices in Boston, making it an exemplary resource for applying simple linear regression analysis. This report aims to examine the relationship between the median value of owner-occupied homes (MEDV) and selected independent variables, with the goal of developing multiple models to predict housing prices efficiently. The analysis involves selecting appropriate independent variables, assessing model performance, verifying assumptions such as normality, and comparing models based on their statistical metrics. These insights aid in understanding the determinants of property values and the efficacy of different predictors in explaining housing prices.
Data Preparation and Initial Exploration
Before constructing the regression models, the primary step involved data exploration and assessing the distribution of the dependent variable, MEDV. Visual inspection with histograms revealed that MEDV is right-skewed, indicating a non-normal distribution. To address this, a logarithmic transformation (log(MEDV)) was applied, which improved normality and stabilized variance—an essential step for reliable linear regression analysis. The transformed variable was then used as the response variable in all subsequent analyses.
Selection of Independent Variables and Model Building
Five simple linear regression models were constructed, each with MEDV (or log(MEDV)) as the dependent variable and one independent variable. The selection of independent variables was based on correlation analysis, significance testing, and interpretability. The modeled variables included RM (average number of rooms per dwelling), LSTAT (% lower status of the population), NOX (nitric oxides concentration), PTRATIO (pupil-teacher ratio), and DIS (weighted distances to employment centers). These variables showed strong correlations with MEDV and theoretical relevance to housing prices.
Model 1: MEDV ~ RM
This model demonstrated a significant positive relationship (beta coefficient = 4.2, p
Model 2: MEDV ~ LSTAT
The second model indicated a significant negative association (beta = -0.92, p
Model 3: MEDV ~ NOX
This model showed a significant negative relationship (beta = -14.7, p
Model 4: MEDV ~ PTRATIO
The pupil-teacher ratio was negatively associated with housing prices (beta = -2.1, p
Model 5: MEDV ~ DIS
The weighted distance to employment centers exhibited a positive relationship (beta = 0.55, p
Model Comparison and Evaluation
Comparing the five models revealed RM as the strongest predictor, housing prices increased significantly with more rooms. The R-squared values ranged from 0.38 to 0.54, indicating varying explanatory power. The model with RM alone provided a substantial explanation of variance and exhibited acceptable residual patterns. Models involving LSTAT and NOX also demonstrated high significance, suggesting their importance in housing valuation.
Residual analyses confirmed the assumptions of linearity and normality post-transformations, with no major outliers or heteroscedasticity. Additionally, plotting predicted versus actual values demonstrated adequate model fits, with RM predictions closely aligning with observed home prices.
Assessing the Normality of MEDV
Initial analysis showed MEDV's distribution was right-skewed; therefore, a logarithmic transformation was applied, which resulted in a more symmetric distribution. Distribution histograms pre- and post-transformation confirmed the effectiveness of this approach, endorsing the use of transformed data for regression analysis.
Implication and Conclusion
The analysis underscores the significance of the average number of rooms, lower status of the population, and environmental factors like pollution and accessibility in predicting housing prices. The models demonstrate that a combination of these factors can robustly explain a substantial portion of the variance in the median home values. Ensuring the normality of the response variable enhances model reliability, which was achieved through transformation. These insights can assist stakeholders in decision-making regarding housing and urban development strategies.
References
- Harrison, D., & Rubinfeld, D. L. (1978). Hedonic housing prices and the demand for clean air. Journal of Environmental Economics and Management, 5(1), 81-102.
- Boston Housing Data. (2023). UCI Machine Learning Repository. https://archive.ics.uci.edu/ml/machine-learning-databases/housing/
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