- IB
- Question Type 15: Performing and entire statistical test
In a study of 100 individuals, 50 smokers and 50 nonsmokers are classified by presence/absence of a respiratory condition: smokers with condition 20, without 30; nonsmokers with 10, without 40. At α=0.05 perform a chi‐squared test of independence between smoking and the condition.
Thirty people are classified by hair color (blonde, brown, black) and eye color (blue, brown, green) with observed counts:
Blond–Blue 5, Blond–Brown 3, Blond–Green 2; Brown–Blue 3, Brown–Brown 7, Brown–Green 0; Black–Blue 2, Black–Brown 4, Black–Green 4.
At 5%, test whether hair and eye color are independent.