Past exam of the mathematics course of the University of Cambridge / 2021 / iii / Paper 207 / 1 / a / iv / Solution

After stroke, absence of a dementia effect on the death intensity is the restrictionFit the unrestricted model and the nested model subject to this equality, then use a likelihood-ratio test. Under regularity conditions, twice the log-likelihood difference is asymptotically chi-squared with one degree of freedom.