13.6 A dataset of size N is successfully fit with a model, to give a fit statistic 2 min. A model with a nested component with 1 additional independent parameter for a total of m parameters is then fit to 2 min, providing a reduction in the fit statistic of

2.

Determine what is the minimum

2 that, in the limit of a large number of degrees of freedom, provides 90% confidence that the additional parameter is significant.