Linear combination of two statistics is considered when some prior knowledge about their expectation and complete knowledge about their joint dispersion is available. The considered setup is more general than those already known in the literature, in the sense that the expectation of one of the...

The best linear unbiased estimator BLUE (CXb) of a linear transform CX b in the general Gauss-Markov model (y, E (y) = X b Cov (y) =a2v) is the linear transform C BLUE (Xb) of the best linear unbiased estimator BLUE (Xb) of Xb. Similarly, for the ordinary least squares estimator OLSE (CXb) = C...