Past exam of the mathematics course of the University of Cambridge 2020 ii Paper 4 5J a iii Solution Created 2026-09-24 Updated 2026-09-29
Past exam of the mathematics course of the University of Cambridge 2020 ii Paper 4 5J a ii Solution Created 2026-09-24 Updated 2026-09-29
The full F-test has and tests the null hypothesis that both slope coefficients vanish. It decisively rejects that hypothesis, while says the fitted model explains about of the sample variation. Together with the insignificant individual t-tests, this is characteristic of multicollinearity: the two covariates explain the response jointly, but the output does not identify either one as having a separately estimable effect.
Past exam of the mathematics course of the University of Cambridge 2023 ii Paper 4 13J ii Solution Created 2026-09-24 Updated 2026-09-25
None of the displayed one-coefficient Wald tests for
team1_form rejects at the significance level. That does not establish that formation has no effect: the relevant null hypothesis sets all nine displayed team1_form coefficients to zero simultaneously, and several individually imprecise estimates may still be jointly significant. One should compare the fitted model with the nested model omitting team1_form by an analysis of deviance for nested generalized linear models, equivalently a likelihood-ratio test of those joint restrictions. Past exam of the mathematics course of the University of Cambridge 2024 iii Paper 207 4 a ii Solution Created 2026-09-24 Updated 2026-09-25
Past exam of the mathematics course of the University of Cambridge 2024 iii Paper 225 2 a Solution Created 2026-09-24 Updated 2026-09-25
Use the test statisticUnder the null hypothesis, the Hilbert-space central limit theorem gives , where is centered Gaussian with covariance . If , its Karhunen–Loève expansion and the continuous mapping theorem givefor independent . Reject for above the quantile of this weighted chi-squared law; replacing the by empirical covariance eigenvalues gives a plug-in estimator of the critical value.
Under every fixed alternative , the weak law of large numbers gives , so and the test is consistent. Under a local alternative , the limit is , which describes its local power.
Scan statistic Created 2026-10-06 Updated 2026-10-07
A scan statistic searches a family of candidate locations or subsets and reports the largest local statistic. Under a null hypothesis, a union bound converts a tail estimate for each candidate into a bound for the maximum; no independence between local statistics is required. Structured alternatives often permit a chi-squared testing lower bound using the overlap geometry of two candidates.
Signed normal Wald statistic 2026-10-06
For an independent normal sample with known standard deviation , the signed Wald statistic for testing mean zero is . It has the standard normal distribution under the null hypothesis and distribution under mean . Its square has a chi-squared distribution; retaining the sign permits a one-sided test.
Size of a statistical test 2026-10-03
The size of a test is the supremum, over distributions in its null hypothesis, of its rejection probability. For a simple null it is just the null rejection probability; a level- test has size at most .
Statistical test Created 2026-10-05 Updated 2026-10-06
A statistical test is a measurable rule for deciding whether to reject a null hypothesis. Allowing randomisation, it is represented by a function giving the conditional rejection probability after observing . A deterministic test takes only values zero and one. Under a simple null, is its size of a statistical test; under an alternative, is its statistical power. Randomisation on a likelihood ratio equality set allows a Neyman-Pearson lemma threshold test to attain a prescribed size even for discrete data.