Past exam of the Probability, statistics and options II course of the University of Oxford / 2009 / O / O5 / ii / Solution

With one parameter fitted to the grouped cells, the reference degrees of freedom are $10-1-1=8$. The table already gives a deviance of $8.29$ at $0.93$, so the minimized deviance is no larger than that; its direct grouped minimum is about $7.76$. Either is below the supplied critical value $15.51$. Therefore do not reject the fitted grouped log-series model at level five percent. The estimate being profiled in this test is the grouped-likelihood estimate described above, not the different full-data score estimate.