CAIE A-Level Further Math 4.4.2 The basis of the sign test
Practise the assumptions behind sign, Wilcoxon signed-rank and rank-sum tests, and how those assumptions affect test choice.
- Syllabus
- 2028–2030
- Course
- Further Mathematics 9231
- Level
- AS
Practise the assumptions behind sign, Wilcoxon signed-rank and rank-sum tests, and how those assumptions affect test choice.
A large number of students took two test papers in mathematics. The teacher believes that the marks obtained in Paper 1 will be higher than the marks obtained in Paper 2. She chooses a random sample of 9 students and compares their marks. The marks are shown in the table.

State an assumption that you have made in carrying out the test in part (a).
The population differences are symmetrical (about the median
difference)
B1
Words in bold, or their equivalent, are required.
1