OCR S4 2013 June — Question 2

Exam BoardOCR
ModuleS4 (Statistics 4)
Year2013
SessionJune
TopicWilcoxon tests

2 Two drugs, I and II, for alleviating hay fever are trialled in a hospital on each of 12 volunteer patients. Each received drug I on one day and drug II on a different day. After receiving a drug, the number of times each patient sneezed over a period of one hour was noted. The results are given in the table.
Patient123456789101112
Drug I1134191610296172013425
Drug II122010183219131019912
The patients may be considered to be a random sample of all hay fever sufferers.
A researcher believes that patients taking drug II sneeze less than patients taking drug I.
Test this belief using the Wilcoxon signed rank test at the \(5 \%\) significance level.