Past exam of the mathematics course of the University of Cambridge / 2019 / iii / Paper 207 / 1 / e / Solution

Use the deterministic evidence-synthesis relationwith supportA uniform prior on this triangle has density $21_{\mathcal{T}}$. Conditional on the prevalences, model the independent surveys bywith the two counts conditionally independent and ${\pi }_2={\pi }_1+\lambda$.