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Linear Regression
vocabulary for linear regression study
| Question | Answer |
|---|---|
| input variable | the independent variable |
| line of best fit | a line whose equation represents the smallest possible differences between the squares of observed minus predicted values on a line |
| linear correlation coefficient | the strength of a linear relationship between two variables, determined by the preciseness of shift in y as x increases. |
| linear regression | the straight line that best describes the relationship between two variables |
| negative correlation | a correlation in which an increase in x leads to a decrease in y. |
| ordered pairs | a mathematical expression (x, y) where x is the input variable written first, and y is the output variable written second. |
| output variable | the dependent variable |
| positive correlation | a correlation in which an increase in x leads to an increase in y. |
| predicted value | the value of y calculated by modeling a particular value of x with a prediction equation. |
| prediction equation | an equation that models a mathematical relationship between x and y with an algebraic expression. |
| scatter plot | a plot of all the ordered pairs of bivariate data on a coordinate axis system. |
| slope | the ratio of the rise over the run of a line. |
| bivariate data | data that describes two characteristics for each observation |
| correlation coefficient | the numerical measure of the direction and strength of a linear association |
| interpolation | using the line of regression to predict a y-value for an x-value within the x-data |
| extrapolation | using the line of regression to predict a y-value for an x-value outside of the x-data set |
| residual | the difference between the observed value of y and the predicted value of y |
| residual plot | a scatterplot of the residuals plotted to the x-values or predicted y-values |
| coefficient of determination | r squared measures the percentage of total variation in the response variable that is explained by the least-squares regression line |