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Last updated on August 9, 2025
In statistics, the coefficient of determination, denoted as \( R^2 \), is a key metric used to evaluate the goodness of fit of a regression model. It represents the proportion of the variance in the dependent variable that is predictable from the independent variables. In this topic, we will learn the formula for the coefficient of determination.
The coefficient of determination, ( R2 ), is used to assess how well a regression model fits the data. Let’s explore the formula used to calculate the coefficient of determination.
The coefficient of determination, ( R2 ), is calculated using the formula:
[ R2 = 1 - frac{text{SS}_{text{res}}}{text{SS}_{text{tot}}} ] where ( text{SS}_{text{res}} ) is the residual sum of squares, and ( text{SS}_{text{tot}} ) is the total sum of squares.
In statistics and real-life applications, the coefficient of determination formula is crucial for evaluating model accuracy.
Here are some important aspects of ( R2 ):
Understanding the coefficient of determination formula can be challenging.
Here are some tips to make it easier:
The coefficient of determination is widely used in various real-life contexts.
Here are some examples:
Students often make errors when calculating the coefficient of determination. Here are some common mistakes and how to avoid them:
Given a regression model with \(\text{SS}_{\text{res}} = 10\) and \(\text{SS}_{\text{tot}} = 50\), what is the coefficient of determination (\( R^2 \))?
The coefficient of determination (( R2 )) is 0.8
The formula to calculate ( R2 ) is: [ R^2 = 1 - frac{text{SS}_{text{res}}}{text{SS}_{text{tot}}} ]
Substitute the given values: [ R2 = 1 - frac{10}{50} = 1 - 0.2 = 0.8 ]
A regression analysis shows \(\text{SS}_{\text{res}} = 15\) and \(\text{SS}_{\text{tot}} = 100\). Calculate \( R^2 \).
The coefficient of determination (( R2 )) is 0.85
Use the formula for ( R2 ): [ R2 = 1 - frac{15}{100} = 1 - 0.15 = 0.85 ]
If \(\text{SS}_{\text{res}} = 5\) and \(\text{SS}_{\text{tot}} = 20\), what is \( R^2 \)?
The coefficient of determination (( R2 )) is 0.75
Apply the formula: [ R2 = 1 - frac{5}{20} = 1 - 0.25 = 0.75 ]
Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.
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