The data values (Vi, X1i , X2i), i = 1, .., 15, are thought to satisfy the model (M2) given by: y = Bo+ B1x1+ Bzxzte, where the response variable y is continuous, the regressor vector X = (X1, X2)' has mean vector (/x1, #x2)' and positive definite variance-covariance matrix Ex , the random errors Er conditional on X, are statistically independent and normally distributed with mean zero and variance o which does not depend on X . The analysis gave R