The formula to calculate the R-squared value is:
\[ R^2 = 1 - \left(\frac{SSR}{SST}\right) \]
Where:
R-squared, also known as the coefficient of determination, is a statistical measure that represents the proportion of the variance for a dependent variable that’s explained by an independent variable or variables in a regression model. It provides a measure of how well observed outcomes are replicated by the model, based on the proportion of total variation of outcomes explained by the model. R-squared values range from 0 to 1, where a higher value generally indicates a better fit of the model.
Example 1:
Step 1: Calculate the R-squared value:
\[ R^2 = 1 - \left(\frac{50}{200}\right) = 1 - 0.25 = 0.75 \]
Example 2:
Step 1: Calculate the R-squared value:
\[ R^2 = 1 - \left(\frac{30}{150}\right) = 1 - 0.2 = 0.8 \]