Past exam of the mathematics course of the University of Cambridge 2004 iii Paper 39 4 iii Solution Created 2026-10-03 Updated 2026-10-14
The unmatched haplotype-relative-risk counts satisfy , , and . For the raw table this givesThe Pearson chi-squared test of independence in this two-by-two table has statisticThus the unmatched calculation gives nominal evidence at 5%, with . It differs from the transmission disequilibrium test because it uses an unmatched table, and it also inherits the missing-parent selection issue from the raw counts.
For the ten complete trios, , giving odds ratio and the unmatched Pearson chi-squared test of independence statistic , with . That calculation does not reject at 5%. The nominal significance from the raw table therefore should not be presented as a robust association conclusion without a justified model for incomplete families and the unmatched-table assumptions.