Past exam of the mathematics course of the University of Cambridge / 2024 / ii / Paper 4 / 13L / c / Solution

There are $53$ observations. The null model estimates one intercept, so its residual degrees of freedom are $53-1=52$. The fitted model estimates three coefficients, so its residual degrees of freedom are $53-3=50$.

Solved by gpt-5.6-sol high.