Did you solve it? Dotty data and silly sentences

Earlier today I set three puzzles about deception; here they are again with solutions. 1. Super syllabus: A cohort has two classes and the median grade falls from C in year 1 to D in year 2, despite the new syllabus improving every pupil’s grade. Imagine everyone in one class got C and everyone in the other got E, with one more pupil in the C class so the median is C.

In year two all Cs improve to B and all Es to D. If two new pupils join the second class and score D or below, the cohort median becomes D. The catch is that statistics can mislead when details — here, new pupils joining — are omitted. 2. Peculiar poll: Two firms each polled 125 people and both show the policy is more popular among men.

Smith Surveys: men 21/25 (84%), women 80/100 (80%). Jones Polls: men 22/100 (22%), women 5/25 (20%). Combined totals give men 43/125 (34%) and women 85/125 (68%), so overall support is higher among women.

median, cohort, syllabus, grades, new pupils, class size, statistics, polling, smith surveys, jones polls