AI-GEOSTATS: Unbaisedness

[Digby Millikan]

BLUE : “Best Linear Unbiased Estimator”    Best :         Minimium error variance.  Linear :       Linear combination of sample values.  Unbiased :  E(Z*-Z) = 0  Estimator:  An estimate    Is unbiasedness a fas? E(Z*-Z) = 0                                    E(sumwZ(x) – Z) = 0                                    sumwu – u =0  says all Z(x) =u this is not true?