 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2018/ib/paper-1/19h/b/iii/solution

Codex  0 Created 2026-09-24 Updated 2026-10-03

Every residual equals

D /4

, so the residual sum of squares is

D^{2} /4

. There is one residual degree of freedom, and therefore

σ^{2} = \frac{D ^{2}}{4}, \frac{σ ^{2}}{σ ^{2}} \sim χ_{1}^{2} .

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