This calculator finds the residual sum of squares (RSS) for a linear regression model using values for the predictor and response variables.
To use the calculator, provide a list of values for the predictor and the response, ensuring they are the same length, and then click the “Calculate RSS” button.
Residual Sum of Squares (RSS):
Residual Sum of Squares (RSS) Explanation
The Residual Sum of Squares (RSS) is a measure of the discrepancy between the observed data and the data predicted by a linear regression model. It is used to evaluate the goodness of fit of the model, with lower values indicating a better fit.
Key Components
- Predictor Variable (X): The independent variable used to predict the response.
- Response Variable (Y): The dependent variable that is being predicted.
- Fitted Value (Ŷ): The predicted value of Y for a given X, based on the linear regression model.
- Residual (e): The difference between the observed and the fitted value, \( e = Y – Ŷ \).
Residual Sum of Squares Formula
The RSS is calculated as the sum of the squares of the residuals:
where \( Y_i \) is the actual value, \( \hat{Y}_i \) is the predicted value, and \( n \) is the number of observations.
Steps to Calculate RSS
- Fit a linear regression model to the data.
- Calculate the predicted (fitted) values for the response variable based on the model.
- Find the residuals by subtracting the predicted values from the observed values.
- Square each residual and sum them up to find the RSS.
Importance of RSS
- RSS is used to measure the accuracy of a regression model. A lower RSS value indicates that the model better fits the data.
- It plays a key role in determining the R-squared value, which is another measure of the model’s goodness of fit.
- It helps to compare different models— the one with the lower RSS generally provides a better fit to the data.
Further Reading
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