Least squares regression line
Gives the straight line that minimises the sum of squared vertical differences between observed and predicted y values. It is used to model and predict a linear relationship between two variables from paired data.
\hat{y} = a + bx, \quad b = \frac{\sum (x_i-\bar{x})(y_i-\bar{y})}{\sum (x_i-\bar{x})^2}, \quad a = \bar{y} - b\bar{x}What the symbols mean
| predicted value of the response variable | |
| value of the explanatory variable | |
| intercept of the fitted line | |
| slope of the fitted line | |
| i-th observed value of the explanatory variable | |
| i-th observed value of the response variable | |
| sample mean of the x values | |
| sample mean of the y values |
About this formula
- FieldStatistics
- TopicRegression analysis
- LevelHigh school
- Also calledlinear regression line, line of best fit, ordinary least squares slope, regression slope and intercept, best fit line formula, OLS regression coefficients
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