OCR Further Statistics AS 2024 June — Question 2

Exam BoardOCR
ModuleFurther Statistics AS (Further Statistics AS)
Year2024
SessionJune
TopicChi-squared distribution

2 For a random sample of 160 employees of a large company, the principal method of transport for getting to work, arranged according to grade of employee, is shown in the table.
GradeWalk or cyclePrivate motorised transportPublic transport
A9136
B164341
C11813
A test is carried out at the \(5 \%\) significance level of whether there is association between grade of employee and method of transport.
  1. State appropriate hypotheses for the test. The contributions to the test statistic are shown in the following table, correct to 3 decimal places.
    GradeWalk or cyclePrivate motorised transportPublic transport
    A1.1570.2891.929
    B1.8780.2250.327
    C2.0061.8000.083
  2. Show how the value 0.225 is obtained.
  3. Complete the test, stating the conclusion.
  4. Which combination of grade of employee and method of transport most strongly suggests association? Justify your answer.