Ap statistics tutorial hypothesis test for slope of regression line, browse by content type
The Y values are roughly normally distributed i. An R2 of 0 means that the dependent variable cannot be predicted from the independent variable. If the equations lead to contrary decisions, use caution.
Many statistical software packages and some graphing calculators provide the standard error of the slope as a regression analysis output. This is called simple regression as opposed to multiple regression, which handles two or more independent variables.
The formula for computing the coefficient of determination for a linear regression model with one independent variable is given below. Suppose Y is a dependent variable, and X is an independent variable.
When the data set includes an influential point, the data set is nonlinear. Use a linear regression t-test described in the next section to determine whether the slope of the regression line differs significantly from zero. Formulate an Analysis Plan The analysis plan describes how to use sample data to accept or reject the null hypothesis.
In the first example above, the coefficient of determination is smaller when the influential point is present 0. Often, researchers choose significance levels equal to 0. Learn How Influential Points An influential point is an outlier that greatly affects the slope of the regression line.