Question 1 - A-Level Maths

Exam Board	CAIE
Module	S1 (Statistics 1)
Year	2016
Session	June
Topic	Independent Events
Type	Independence in contingency tables

1 In a group of 30 adults, 25 are right-handed and 8 wear spectacles. The number who are right-handed and do not wear spectacles is 19 .

Copy and complete the following table to show the number of adults in each category.
Wears spectacles Does not wear spectacles Total
Right-handed
Not right-handed
Total 30
An adult is chosen at random from the group. Event \(X\) is 'the adult chosen is right-handed'; event \(Y\) is 'the adult chosen wears spectacles'.
Determine whether \(X\) and \(Y\) are independent events, justifying your answer.