Yates' correctionAQA A-Level Further Maths: Mind map

Exam questions on Yates' correction

1. A gardener compares germination for 60 seeds given fertiliser and 60 seeds given none. Of the seeds given fertiliser, 42 germinate. Of the seeds given none, 30 germinate. A chi-squared test for association between treatment and germination is to be carried out.
   State the degrees of freedom of the test statistic and explain why Yates' correction is applied.2 marks
2. A survey of 50 people records which of two products, A or B, each prefers. Of the 30 men, 20 prefer A and 10 prefer B. Of the 20 women, 6 prefer A and 14 prefer B.
   Calculate the value of the test statistic with Yates' correction applied.2 marks
3. A trial compares two treatments for a skin condition. Of 20 patients given treatment A, 14 were cured. Of 20 patients given treatment B, 8 were cured.
   Calculate the value of the test statistic with Yates' correction applied.3 marks