ols residual vector definition which residual vector does ols use which is the covariance matrix of a lls residual vector what is the variance coefficient of the ols residual vector what is the variance matrix of the ols residual vector? how to solve it? what is the coefficient of variance for ols what is the variance coefficient what is the matrix of the variance which residual value is the variance covariance of the OLS residual vector? what is the variance-covariance matrix of the ols residual vector? what is the variance coefficient matrix in lls what is variance of coefficient what is the variance covariance matrix of the ols residual vector what is the variance covariance matrix in an ols regression what is variance coefficient of ols what is the variance covariance matrix of the ols residual vector variance coefficient of equation what is the variance coefficient in a residual vector what is the variance matrix what is the variance variance matrix and the coefficient matrix