39In the parentheses we see the confidence level. This is defined as the probability that the parameters are within the range defined by the error. For a correct calculation of the confidence level, every point should be weighted by its error - in our example this is not happening and this is the reason why the confidence level is so low. A value below 5% is too low and it indicates that the model needs corrections. It is also assumed that the distribution of the measurements is Gaussian and if not, the computed numerical values are only indicative.