In matrix terms, the formula that calculates the vector of coefficients in the model is:
Term | Description |
---|---|
X | design matrix |
Y | response vector |
The standard errors of the coefficients for multiple regression are the square roots of the diagonal elements of this matrix:
Term | Description |
---|---|
X | design matrix |
X' | transpose of the design matrix |
s2 | mean square error |
Term | Description |
---|---|
test statistic for the coefficient | |
estimated coefficient | |
standard error of the estimated coefficient |
The two-sided p-value for the null hypothesis that a regression coefficient equals 0 is:
The degrees of freedom are the degrees of freedom for error, as follows:
n – p – 1
Term | Description |
---|---|
The cumulative distribution function of the t distribution with degrees of freedom equal to the degrees of freedom for error. | |
tj | The t statistic for the jth coefficient. |
n | The number of observations in the data set. |
p | The sum of the degrees of freedom for the terms. The terms do not include the constant. |