Past exam of the mathematics course of the University of Cambridge / 2022 / ii / Paper 1 / 13J / c / Solution

The residual deviance per residual degree of freedom isreasonably close to one. The first and third quartiles of the deviance residuals, $-0.591$ and $0.621$, are also fairly close to the standard-normal quartiles $\pm 0.674$. There is mild evidence of underdispersion, but nothing in this summary makes the binomial value one plainly unreasonable.