Use this field to specify the optional variable that indicates the relative weights for a weighted least squares fit.
If the weight value is proportional to the reciprocal of the variance for each
observation, then the weighted estimates are the best linear unbiased estimates (BLUE). Values of the weight variable must be
nonnegative. If an observation’s weight is
zero, the observation is deleted from the analysis. If a weight is negative or
missing, it is set to
zero (0), and the observation is excluded from the analysis.